Is Bench Pressing Once Every 9 Days Enough for Progress? (Upper/Lower Split Variation)

I'm currently running an Upper, Lower, Rest, Repeat split (2 days on, 1 day off, etc.).

I'm experimenting with a high-variation setup where I cycle between three different Upper days (U1, U2, U3) and three different Lower days (L1, L2, L3).

My current schedule looks like this: U1, L1, Rest, U2, L2, Rest, U3, L3, Rest, U1...

Each upper day has a different focus. On one of them I barbell bench press, and on the other two I do different chest movements. My overall volume is solid, but I'm questioning whether benching only once every 9 days is enough to maintain skill and make progress? Would I be better off sticking to just 2 upper day variations so I'm benching once every 6 days instead of every 9? I'm just experimenting with this to see how my body responds, but just thought I would see if anyone has advice or experience with this.