user24016: I usually have problems with the light-squared bishop when Black takes it out of the pawn chain and doesn't exchange it, but instead either protects it with the e-pawn:
rn1qkb1r/ppp2ppp/4pn2/3p1b2/3P1B2/3BP3/PPP2PPP/RN1QK1NR w KQkq - 0 5
1. d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Bd3 e6

or moves it back to g6:
rn1qkb1r/ppp1pppp/5nb1/3p4/3P1B2/3BP3/PPP2PPP/RN1QK1NR w KQkq - 3 5
1. d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Bd3 Bg6

If I exchange bishops, then Black will have either a very strong control of e4 to place a knight (when protected by the e-pawn), or a semi-open file for the h-rook (when in g6). If I don't exchange it, then the constant threat of Bxd3 hinders my development; I can't play the usual London moves c3, Nbd2 and my queen has to keep an eye on protecting the bishop.
In all videos about the London that I've seen, it's assumed that Black will keep his light-squared behind the pawn chain or will exchange it in d3. How do you deal with it when in those other cases?

user-1: White is standing all right. You can develop without any hindrance. I don't see how Bxd3 is a threat. It's not.
[Fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1. d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Bd3 e6 5. Bxf5 exf5 6. Qd3 Qd7⩲ 

If 6... g6 then 7. Qb5+ Nbd7 8. Nc3 Bd6 9. Nge2± or 8... Bg7 9. Nf3 0-0 10. Nxe5 and White has advantage.
As to your second variation, there are a lot of maneuvering possible. Or White expects to win in one fell swoop? I don't think it's going to be the case. For example, 1. d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Bd3 Bg6 5. Nf3 e6 6. 0-0 Bd6 (6... Ne4 7. Ne5 Bd6 8. Nd2 Nd7 9. Nxe4 and White is doing really fine. White is a tempo up) 7. c3 and White is fine again, e.g. 7...0-0 and now White can take the bishop: 8. Bxg6. It's about equal. Also White is not obliged to play 4. Bd3:

d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Nd2 e6 5. c4 Bd6 6. Bxd6 Qxd6 7. c5 Qe7 or some other lines. Again too many variations and maneuvering is possible. In other words 1. d4 d5 2. Bf4 Bf5 is not some wrong line for Black; it's fine, which means White can't capitalize right away. It's going to be a long battle.

If Black doesn't want to exchange the bishop, it is his problem, not White's. White has plenty of options and he's not a tempo down.

user4418: Actually Simon Williams, the GingerGM has covered these cases in his videos on the original London System and the Jobava London.
He has two suggestions.
The first is to switch to a QGD setup with c4 followed by Nc3 and possibly Qb3 to hit both the b7 and d5 pawns. Williams covers the slightly scary looking response BxNb1 followed by Bb4+ from black and shows that white gets a perfectly good game.
The second is to transpose to something like a Jobava London / Veresov setup with f3. The ides here is to grab space on the kingside with g4 and possibly also h4.
The key, as always in opening play, is to not play in a formulaic way just bashing out the same moves regardless of what your opponent does. Instead you need to be able to react and change your plans to take advantage of variations your opponent might play.

24016: <p>I usually have problems with the light-squared bishop when Black takes it out of the pawn chain and doesn't exchange it, but instead either protects it with the e-pawn:</p>
<pre><code>rn1qkb1r/ppp2ppp/4pn2/3p1b2/3P1B2/3BP3/PPP2PPP/RN1QK1NR w KQkq - 0 5
1. d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Bd3 e6
</code></pre>
<p>or moves it back to g6:</p>
<pre><code>rn1qkb1r/ppp1pppp/5nb1/3p4/3P1B2/3BP3/PPP2PPP/RN1QK1NR w KQkq - 3 5
1. d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Bd3 Bg6
</code></pre>
<p>If I exchange bishops, then Black will have either a very strong control of e4 to place a knight (when protected by the e-pawn), or a semi-open file for the h-rook (when in g6). If I don't exchange it, then the constant threat of Bxd3 hinders my development; I can't play the usual London moves c3, Nbd2 and my queen has to keep an eye on protecting the bishop.</p>
<p>In all videos about the London that I've seen, it's assumed that Black will keep his light-squared behind the pawn chain or will exchange it in d3. How do you deal with it when in those other cases?</p>
 -1: <p>White is standing all right. You can develop without any hindrance. I don't see how Bxd3 is a threat. It's not.</p>
<pre><code>[Fen &quot;rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1&quot;]

1. d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Bd3 e6 5. Bxf5 exf5 6. Qd3 Qd7⩲ 
</code></pre>
<p>If 6... g6 then 7. Qb5+ Nbd7 8. Nc3 Bd6 9. Nge2± or 8... Bg7 9. Nf3 0-0 10. Nxe5 and White has advantage.</p>
<p>As to your second variation, there are a lot of maneuvering possible. Or White expects to win in one fell swoop? I don't think it's going to be the case. For example, 1. d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Bd3 Bg6 5. Nf3 e6 6. 0-0 Bd6 (6... Ne4 7. Ne5 Bd6 8. Nd2 Nd7 9. Nxe4 and White is doing really fine. White is a tempo up) 7. c3 and White is fine again, e.g. 7...0-0 and now White can take the bishop: 8. Bxg6. It's about equal. Also White is not obliged to play 4. Bd3:</p>
<ol>
<li>d4 d5 2. Bf4 Bf5 3. e3 Nf6 4. Nd2 e6 5. c4 Bd6 6. Bxd6 Qxd6 7. c5 Qe7 or some other lines. Again too many variations and maneuvering is possible. In other words 1. d4 d5 2. Bf4 Bf5 is not some wrong line for Black; it's fine, which means White can't capitalize right away. It's going to be a long battle.</li>
</ol>
<p>If Black doesn't want to exchange the bishop, it is his problem, not White's. White has plenty of options and he's not a tempo down.</p>
 4418: <p>Actually Simon Williams, the GingerGM has covered these cases in his videos on the original London System and the Jobava London.</p>
<p>He has two suggestions.</p>
<p><a href="https://youtu.be/_KahCgu1u7w?t=1283" rel="noreferrer">The first</a> is to switch to a QGD setup with c4 followed by Nc3 and possibly Qb3 to hit both the b7 and d5 pawns. Williams covers the slightly scary looking response BxNb1 followed by Bb4+ from black and shows that white gets a perfectly good game.</p>
<p><a href="https://youtu.be/bPLrXjQyNFQ?t=599" rel="noreferrer">The second</a> is to transpose to something like a Jobava London / Veresov setup with f3. The ides here is to grab space on the kingside with g4 and possibly also h4.</p>
<p>The key, as always in opening play, is to not play in a formulaic way just bashing out the same moves regardless of what your opponent does. Instead you need to be able to react and change your plans to take advantage of variations your opponent might play.</p>
