I don't know about the GUF2 being restricted to a booking of 4.

But yes, regarding separate 241, you can't do that as you'd have to be on each one.

You would have also come across the hurdle that, if you are doing a 4-4-2, all 4 of you have to book into the same cabin: you can't do 2J 2F, for example. I don't think they would waive this even if you were concurrently GUF2'ing the 4 of you back together.

It seems totally in the spirit of the 241s and the GUF2 that you should be able to do what you want, and simply a behind-the-scenes process to charge the appropriate taxes, miles and vouchers, but I'm afraid you are unlikely to get special treatment.