(You've invited opinions, & this is mine, should anybody feel like doing a bit of sniping....)
If you can conveniently, reliably rubber mount a carburettor, it must surely be best to do so.
Unfortunately, as can be judged from the many experiences on this Forum, there can be problems & my belief is that you should be very selective as to what mount is chosen, the rubber shouldn't be too hard, the location ribs/groove(s) must match the carburettor/manifold & the hose clips should be of the correct width & not over tightened.
Personally, although the thought had crossed my mind, I wouldn’t go to the trouble of converting a solid mount (an Amal Mk 1 or VHB, say) if there could be a sprung float needle tip fitted, as in the case of the VHB which can take the type fitted to SH2/22’s.
On the other hand, rubber mounting of the exhaust can reap many benefits, Clubman type included.....
