When do you like to transplant?

[lek]

some pepper varieties i sow seed in 9oz cup and never transplant at all.  if you take a look closely, you will see that cotyledon is still there.
 

 

 
 
 
 

 

[U)<now]

 
as for bigger container, i did experiment with Capsicum Chinense.  it will look like this.  
 

Well they certainly do look healthy, a bit lenky, but healthy looking none the less. For me, here is the difference between potting up to #1 pots at first set of true leaves, vs. leaving my extras/spares I leave in starter cells/trays.

 

[U)<now]

some pepper varieties i sow seed in 9oz cup and never transplant at all.  if you take a look closely, you will see that cotyledon is still there.
 

 

 
 
 
 

Yeah that makes sense if you're not looking for huge plants outdoors. Looks like you are growing them in an office of some sorts.

 

[alkhall]

I start in 30mm coir plugs, transplant into 3 inch pots when second set of true leaves appear.