My "Big Jim" hatch chile plant isn't looking very big yet. The Guizeppi Milds and California Wonders are doing a bit better. This was the first day I took them all outside for a few hours to start the hardening off process. I've had them inside with a fan and grow lights up until now.
I expected some flowering at this point, but it's been stupidly cold and rainy here since I planted back in late March (I'm in 6a/6b), so maybe I'm expecting too much too soon? Next week is the first week it will in theory be above 55 degrees F overnight.
I've also been battling gnats (sticky traps and mosquito dunks for the win), which is weird to me because with the fan, the top layer of soil dries out pretty quickly, but I think I have them managed now.
I would say heat and light are the two big things pepper plants love.
I put some pre-seeds into the a raised box 30 days ago, and they are 3x that size easily. I'm in an 8b flipping 7a though. Lots of light throughout the day, but cold temps at night now which is unheard of for this area.
These plants thrived during the hot days though. Some even started fruiting when too low to the ground.
If these aren't in direct sunlight for 6+ hours a day with 70F or better temps, they will be on the smaller side. Maybe consider getting a heat mat if they aren't ready for the outside environment yet.