As far we stack VST effects in BIAB, we don't know if the CPU runs at 30 or 80%. So, it should be very useful to have - inside BIAB - a visual indicator for CPU activity and for RAM load. Up to now, under WIndows, we have to hit CTLR + ALT + DEL to acces to CPU activity monitor.
Furthermore, it would help in VST selection : for ex. some VST effects of a same familty require much CPU power than others : for ex. a VST equalizer1 could require 30% of CPU power. So, in this case, we have perhaps to remove a VST in order to lower the CPU activity level.
Many other great music softwares offer this feature.
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Reach for excellence

There are plenty of great aftermarket CPU and Resource monitors to be downloaded for free...

The Windows Task Manager can be made to start with Windows, and the CPU Resource Meter to run in the tray when Task Manager is minimized.

Mix the tracks and effect them to taste then turn them into finished wave files and re import. then you do not need effects.

I know all that. I already use an aftermarket CPU and Resource monitor.
The goal is to get a more modern BIAB with integrated features without the need to open simultaneously 10 softwares in order to get full useful functionalities.
In this case, the BIAB piano roll is not necessary : many sequencers offer one ; the BIAB wave editor is not required, there is Audacity, etc..