I have a 2023 Checkpoint SL5. The 2X drive trains 11/34 in the rear. You can run a 11/40 and some have used 11/44. Crank it comes with either Praxis or GRX. The GRX is 46/30 and Praxis is 48/32 I think. The Praxis low may be a 31. I have GRX. The new, latest Generation of the Checkpoint currently only comes in 1X with SRAM groupset. The newest design can run 2X but the bracket for a front derailleur is extra. The SL has mounting holes. The ALR would clamp on. As for the 50/34 crank the frame will accommodate this but does not come with it. This is the largest size that will fit.

Ryan Van Duzer did a cross country trip with a Checkpoint. He has a series of videos and shows what they packed. There is also another guy who did a cross country trip. He broke the flange on the stock wheelset and had to replace the rear wheel during the trip. I get the impression the stock wheels are the weak link.