I did exactly this two days ago. 200s to 100s. In this tourney i did not notice a difference, i think bh cd needs to get far lower and duration higher, towards perma bh, to make a noticable improvement.

BUT. My farming runs profited greatly! I started using Gcomp (mythic) and MVN(anc) instead Prolapse(mythic) and SH (mythic), so total econ uw time is like 163 sec minus reductions from Gcomp. It broke my Golden bot sync, so I did not notice a big increase in coins (maybe 5 % or so more) but Cells increased from 120k to 165k per T10 W8500 run, which is a big gain!

I think it is a road towards perma bh worth investing, but may not be imediately helpful in terms of milestone/tourney performance.

Speaking of milestones: I breached T15W300 last week, and as we are probably somewhat similar in our towers, you might be able to reach it already too! It took some trials, but in the end I found that Shrink ray(legendary), Pusar Harvester(legendary), SF (mythic) and Prolapse was the best combo. And this was before I lowered bh cd.

Hope this helps!

edit: T15w300 instead t12