With my Nikon D5500 I didn't consider EC was useful when discussions went to use EC.
Very recently I discovered that I can use EC, Exposure Compensation., with my OM-D E-M5 iii.
Menu->Button Functions->+/--> select Exposure +/- (usually the default).
Next scroll down to Dial Function->scroll down to M/B select front dial to +/-.
Now when auto-ISO it will adjust the ISO within the Auto ISO settings.
Other camera Olympus/OM System bodies may have different Menus.
Other manufactures mirrorless bodies may have similar functionality.
Please let us know about your camera in the comments.