Perhaps this bug interfered with OmeletGuy’s experiment:
https://forums.comodo.com/anti_virus_bugs/do_not_scan_larger_than_setting_ignored_v3995478509_x32-t40012.0.html
“Total objects scanned” in the manual scanner display indicates if a file is not scanned at all.
On my PC, which has a solid-state disc, files < 20MB scan so quickly with CIS that I don’t see a CPU spike.
