Yes, I adjust for 0db in the Scene Leveling tool and the output block, and then my solo bumps it +3-ish DB for solos.
If your IEMs are good quality and reasonably flat, then I'd say to use those to audition and tweak the sound you hear.
I'd probably put a GEQ or PEQ at the end of the chain, prior to the OUT block that feeds the IEM, and tweak that to my taste, and send an unmodified feed directly to FOH and let that engineer adjust the EQ for the house.
@Cooper Carter has a
lot of experience dealing with IEMs on stage and his video about setting up their sound is useful. I'd definitely go with any recommendations that Cooper offers.