Most "flex" or "soft" mounts are junk. They simply transmit too much energy into the airframe and really don't do much isolation.
Not so, they do a great job.
So your homebrew, TLAR mount works? Good on ya. The soft mounts have been around since the '80's at least, and still do well in the market. They transmit LESS energy in a less violent form to the airframe. Hard to figure how your homemade version could be much different.
I've had a couple H9 ARF nylon fiber mounts flex, plus their thin firewalls flex. My Tango mount luckily broke on landing rollout, second one to fail. Going to a cast mount now.