Random thought on soft mounts..If you run a twin there's no reason for an soft mount...
There are very few giant scale glow engines...Largest I can think of is the ST4500...
There is no physics behind glow VS gas..An engine will shake exactly the same no matter what fuel is used, the rotating parts don't change, you can NOT perfectly balance a single...
Some of our giant scale reaers used Q75 singles, never needed an isolation mount...
A 5.8 Sachs single will shake the muffler loose when soft mounted...
Slimline uses have an extra brace for their Pitts style mufflers and does NOT recommend soft mounts..
The Hyde soft mounts I have seen are so soft they put a ring on the front of the engine to help support it..However they seem to work well....Maybe they've since changed, it was years ago...