New MCH looks fine to me. To be perfectly optimal you might have to single-weave Gauss Round and Ricochet during Overheat periods, but if you don't then it's not a huge loss. Because of the 15s refresh effect on Gauss Round and Ricochet caused by Heat Blast, just 6 Heat Blasts is enough to refresh all your stacks from 0, so it is likely that it will be optimal to single weave at least one or two Gauss Round/Ricochets during Overheat. So there may be a need to single-weave between Heat Blasts, but as long as you make sure you have depleted all your Gauss Round and Ricochet stacks before entering Overheat, you are probably not losing out on TOO much damage if you simply don't use oGCDs at all during Overheat.

From looking at the changes it -does- look like single-weaving between 1.5s Heat Blasts is encouraged (not just Gauss Round and Ricochet but Hypercharge too), which is a bit of a problem for me since 1.5s is too short for me to single weave with my ping. But I think if you live in the same region as the servers it should be fine.

If it were me, I would change Gauss Round and Ricochet so either Heat Blast only refreshes maybe 6-10s of each of them, and I would maybe alter Hypercharge so that instead of just being a flat exchange of 50 heat to 8s of Overheat, you could also get 12s for 75 Heat and 16s for 100 Heat off 1 button press (instead of having to extend it manually). That should totally eliminate the need for weaving between Heat Blasts.