Why does D+ cause apps to use 100% cpu and hang?

Disable D+ fixes this problem.

Does disabling D+ disable image execution protection too, becuase this is the main thing from D+ that I’m interested in.

Also, what does cmdagent do? Can I disable it from start if I don’t use Comodo AV?

What applications are being effected here? As to the why of the question I think that is up to the devs or other experts.

cmdagent is the core component of CIS, You should not disable it. You could disable Cfp.exe … but you wouldn’t get the alerts.\Interface