Taking the idea from CFMOTO Side Rider's video:

I added spacers between the driver's seat and seat bracket. The rails are a piece of scrap 2x4 split into two 2x2s, and the center piece is just a length of scrap 2x6. The extra 1.5" of legroom is great and makes a huge difference for me, not just because I am less cramped but entry & exit are far easier.

Instead of getting fancy with slots, I just measured carefully and drilled two oversized holes in the rails where the seat is as far back as it can go. The 2x6 center piece is held to the bracket by four self-drilling screws with washers.

What length bolts did you use?

What length bolts did you use?

60mm was the best size I could find at Home Depot. I think a few mm longer would have been better but they worked ok.

Good to know, thank you!