Some other thoughts..
DOMS can be increased and repeated bout can be mitigated by training less often, say each muscle trained once a week or less often than that, as some do now. What that tells me is that DOMS may be important but isn't soley responsible for growth, given that the majority of great BBs hit the muscle twice weekly for size during the last 4 decades or so. That amounted to greater repeated bout and lesser DOMS after each workout, as the muscle aclimated to greater frequency. That also meant that full recuperation happened more quickly due to repeated bout. Recuperation which most think as i do is as or more important than DOMS.
With no clear answers i think anecdotally DOMS is likely a key ingredient, thus it's smarter to play the odds and shoot for DOMS as often as possible in the absence of conclusive evidence. However, if DOMS were the only critical element, as opposed to say recuperation, less frequent training would always prevail and be considered superior, which it isn't. DOMS is important, within a context of other factors that includes more frequent training of the muscle after recovery, and the use of moderately heavy weights, moderate reps and high training intensity.