I honestly don't think you can connect the forward ones while the mast is down....
Joe is correct - you can't step the mast with the forwards connected. If you like, you can connect them when the mast is flat and forward in its trailering position, to keep the ends from flopping around while towing, but you'll have to disconnect them to slide the mast back all the way before stepping it.
The quick-release levers Joe referred to are something like
these. I haven't used them, but some people really like them, for the forward lowers and/or the forestay.
Some people use
ball-lock pins in place of clevis pins on the forward chainplates, so it's quicker to attach / detach. I did for awhile, but decided I didn't like that they're hollow (allowing for the mechanism), so not as strong as solid clevis pins. So I use standard clevis pins with cotter rings (instead of cotter pins), which is pretty quick.
You can leave the uppers and the aft lowers connected full-time (so normal cotter pins are fine for those).
BTW - there's a (very active)
C-22 subforum on this site. Some of the C-22 sailors mostly hang out there, so for C-22 specific questions, you'll do well to post in that area. And spend some time reading through historic threads in that area. You'll learn a lot.