Catalyzes the exchange of the acyl chain in acyl-dihydroxyacetonephosphate (acyl-DHAP) for a long chain fatty alcohol, yielding the first ether linked intermediate, i.e. alkyl-dihydroxyacetonephosphate (alkyl-DHAP), in the pathway of ether lipid biosynthesis. a 1-acylglycerone 3-phosphate + a long chain fatty alcohol = 1-O-alkylglycerone 3-phosphate + a long-chain fatty acid + H(+) 1-hexadecanoylglycerone 3-phosphate + hexadecan-1-ol = 1-O-hexadecylglycerone 3-phosphate + H(+) + hexadecanoate 1-hexadecanoylglycerone 3-phosphate + a long-chain fatty acid = a 1-acylglycerone 3-phosphate + hexadecanoate Glycerolipid metabolism; ether lipid biosynthesis. Homodimer. The disease is caused by variants affecting the gene represented in this entry. Belongs to the FAD-binding oxidoreductase/transferase type 4 family.