trust the apex more, my inkbird is slow to respond and has bigger swings for some reason, set at 78, shows 76.4 sometimes. (new with aquarium probe, heat only)
i would set the temp in the apex, and inkbird in case something went wrong,
think of the inkbird as the heater thermostat, you can turn them on and off as well. i have my finnex controller on my neptune heater outlet, then my finnex titanium into that. i have another jagger heater a few tents lower to turn on, good for water changes if a tic lower, and will kick in if/when my titanium tube poops out.