9.5 out of VST performance, freeze FX channel?

Hi, I upgraded to 9.5 mainly because of more inserts. Now I can do more things I was used to do in other DAWs (eg. Reaper).

The problem is that I hit the VST meter very soon.

I use method that is used by other pro producers. Split bass to 3 sends and every send will have its own frequency band. Then send all loops to other channel for sidechain. Then send kick & snare together and glue them with compressor. Then two other similar subgroups. After it, send it to master with additional FX.

So I ended like freezing all VST instruments and their insert channels, but still I have spikes in VST performance meter.

And I found out that for some magical reason it is not possible to freeze FX channels. Therefore it looks like my problem has no other solution than export all tracks and mix it in Reaper, which is using a separate thread for every VST or a group of VSTs and this will never happen. What happens is CPU spike, when I have over 200 plugins. But in Cubase I have CPU around 30% and there is some other VST limit that prevents to use my CPU to 100%.