The only place I prefer 2 pieces over 1 piece is on ladies at the beach.
What’s driving your preference for 2 piece bases? Weight? Port clearance/access?
Not for nothing, but if I found myself wanting 2 piece pic mounts, I’d consider cutting apart a quality 1 pc from a proper maker before I dug to even the second or third tier of more obscure manufacturers. I’d also be tempted to bed the rail before cutting to better ensure alignment after the cut. I’ve also milled (and “milled”) bevels into a lot of 1 pc mounts to offer more port access.
But I’d almost always prefer 1pc mounts - we asked for that kind of solution for a long, long time before pic rails finally became broadly available, and now we have them.