Some mfg say it is ok to use vibration mounts others say no don’t do it. So lets see by a show of hands who uses what to mount the gas burners?

Hard mount the engine, soft mount or pad everything else.
Soft mount that engine (especially with a single cylinder) and you'll turn that airframe into a paint shaker.

The problem with available soft mounts is mostly economic, nobody will buy them so nobody has designed a good one. How many will spend $100-$200 on something that reduces performance when they can get by without it. I have seen large diameter Hyde style mounts work well but they can be difficult to adapt to some airframes.