I had 4 months of 110v built-in charging only. I used pre-conditioning on a schedule. My experience consistently was that if the charge hadn't completed yet, then pre-condition would skip. Most days my car would have a full charge before pre-condition tried to begin, and worked fine.
So it worked fine, with the charger attached provided the car was already fully charged. Every once in awhile, I got home late, and there wasn't enough time to complete charging. Also on days when all worked, pre-condition would go but it would drain the battery slightly, then begin charging again automatically (110v still plugged in).
I also had 100% success with pre-conditioning when not plugged into power -- using honda link app or key fob. So not plugged in worked fine.
( I mean to say only attempted when I had at least 50% battery left. I don't know at which level pre-conditioning doesn't work due to low battery.)
-Dan
PS I have touring trim in case it matters. I later bought a level 2 charger which I do recommend.