The goat happens because too little spring.
Engine shouldn’t bounce
Fixed possibly by lighter weights stronger spring or launch lever to stop bounce with your foot.
Yeah you have to tube it to achieve that balance.
Sometimes if it bounces you just need more spring, period. They sell aftermarket springs or you could mod your frame like I did to use a scooter contra spring. It’s the perfect solution to all moby spring issues. So many choices in springs to try for cheap