If I understand correctly an add-on is enabled / disabled across the Anki installation and is not specific to a profile.
Most of my profiles have FSRS enabled but one doesn’t. When I do my reviews in that profile, I get the error message “Please either enable FSRS in your deck options or disable the FSRS helper add-on”.
Can I safely ignore this, or am I going to end up with scheduling errors if I leave the setup as it is?