Yes, that's the plan. The worst part is the step up in price for the HD12, because that seems to be just about right for this use. In my mind, subs are an assumed part of the upgrade process. But, as I recall early in the thread, the idea was switching to two 735's as tops without subs because they can handle that amount of low end. Which also made them suitable for backline situations, while also being a dead-simple setup.
Thank you both for your thoughts. The one takeaway from this thread seems to be to try it out in person, and buy used. Bring over my rig, and some recorded music. Because really, especially with QSC's recent marketing moves, every PA company wants to make it seem like their speakers do more of everything than ever before. My core concerns are, as I think for many people here, weight and sound quality. Which, as I'm beginning to understands forms two parts of the "good, fast, cheap; pick two" saying. And cheap seems to be the excluded factor in my priorities.
Really, I'm in no rush to get this formed, just scouring to see if other people have made more budget options work. That's one half-solid recommendation for the HD10's in a context where upright was used, so I'm guessing few heavy-handed rock drummers were involved. But of course, finding another speaker that works in both contexts at around the €500-€600 price range instead.
Which all, funnily enough, would probably cost as much as just buying the 735's (or 732) from the get-go, just as all the other cost-analysis from the early days of this thread. Darn, this just keeps looping around. Maybe the answer is to just wait.
If someone else has any experiences at all in a more budget setting, please do share.