It seems even with your focus on performance it was still not enough.
With 2882 Belt balancers on the map it was causing a processing time of 7.9 mS. This was 50 % of the processing time budget.
On average that would put the processing time per block at 0.0027 mS or 2.7 uS. I think the performance would need to be an order of magnitude higher for it to no longer be a worry.
Love the mod but it does not seem usable in the mega saves.
Source: https://youtu.be/2ZcqJb5qHrU?t=1260