@scoutldr, it's S-T-2-1 now.
S2FC for "Scout to First Class", or
T2FC for "Trail to First Class" if you want to keep the old shorthand under a different meaning.
I outright banned participation. (Okay, not exactly banned. Strongly emphasized that no 1st year had to attend our camp's program.)
Those scouts who already learned first class can occupy their free time teaching our those skills to 1st years. If nobody in camp knew a skill, they could then schedule an open period with the S2FC camp counselor. Or not. I didn't care and the SM was okay with that.
The downside: because we went through three years of cross-overs going to another troop, I am paying the price now with a few venturers who are week on the orienteering (among other things). That limits their program choices. But it's a mixed group. Some who attended the S2FC program at camp, some who didn't. The real problem is a "once and done" and "no time for next level challenges" attitude that had set in. Since they weren't under the gun to teach a bunch of first-years at camp, they blew off camporees and such and got pretty rusty.