field equations of a generic Quadratic Gravity theory form a highly complicated system of fourth-order nonlinear PDEs. Only a few nontrivial exact solutions are thus known so far, and various approximative and numerical methods have had to be used in their studies. Specifically, in the new class of black holes presented in [@LuPerkinsPopeStelle:2015], the two unknown metric functions of the standard form of spherically symmetric metric were given in terms of two complicated coupled ODEs which were (apart from the first few orders in the power expansion) solved and analyzed numerically. Interestingly, all QG corrections to the four-dimensional vacuum Einstein equations for constant Ricci scalar are nicely combined into a conformally well-behaved Bach tensor. Together with a conformal-to-Kundt metric ansatz [@PravdaPravdovaPodolskySvarc:2017], this leads to a considerably simpler autonomous system of the field equations. We employed this approach in our recent letters [@PodolskySvarcPravdaPravdova:2018] and [@SvarcPodolskyPravdaPravdova:2018] for vanishing and nonvanishing cosmological constant, respectively. In [@PodolskySvarcPravdaPravdova:2018] we were thus able to present an explicit form of the corresponding nontrivial black-hole spacetimes — the so-called *Schwarzschild–Bach black holes* with two parameters, a position of the horizon and an additional Bach parameter. By setting this additional Bach parameter to zero, the Schwarzschild metric of General 