If he works good in that, then go ahead and keep him in it if you want to. However I do not have a horse that likes that bit, it is poorly designed and pretty harsh.
If I had a colt going to be bitted up a bit more, I would put him in one of these bits:
This is a Billy Allen shank bit. The shanks are 8'' with a very nice barrel mouthpiece that doesn't pinch but its still broken in the middle so there's lift and the ability still for some flexion. It's a nice snaffle-to-leverage transition bit. My older barrel gelding really likes this bit, as does my little reining filly.
This next one nobody on this forum seems to like, but recently I had a lot of success with it on my own mare and a clients young horse who needed to go up. Still experimenting with it myself. It is a Sharon Camarillo Sweet Six bit, with the iron wrapped O ring mouthpiece. There's a slight gag and leverage but not a huge amount.
Now this is one I know a lot of people like. These are several forms of the Jr. Cowhorse bit.
^ Of these, I like the twisted dogbone and the copper roller best. It's a personal preference but I don't like single joints so much, althought a lot of other riders do and some hroses do work well off them. On the chain one, that is very hit and miss. Some horses absolutely adore chain mouthpieces, but the others hate them. I personally do not have a horse that likes one.
Those are just my personal opinion as to what I would do in this phase for a younger horses to get him into a competition bit.