Huzzah something I can answer pretty confidently!
In that case, and you are planning to flat hop it, I would go ahead and flat hop it. No time like the present if you have to replace the bucking anyway. If it was me, I would purchase the Prometheus moundless hop up bucking and the Prometheus Flat hop nub or bridge. The difference in the nub and the bridge, is the bridge is curved a little like an r-hop while the flat nub is of course flat. The bridge is supposed to be better but I haven't had the opportunity to use one so i can't say that for sure. At the time I installed the flat hop on the DMR, Promy had not yet come out with their moundless bucking . So I turned a Madbull Fishbone bucking (the black one, DMR shot too hot for the white one) inside out and carefully cut the mound out, and we all know how good that worked. I would expect the Promy moundless will work better since they were made to be used with the flat nub or the bridge.
Oh one more thing, I did have to cut the bucking to make the c clamp fit. That's no big deal and I have had to do it every time I've changed a bucking.