The M300 is an awesome platform, and to increase the longevity of your vibration isolator, I recently purchased these Gremsy Dampening system for the M300 and they work great!
→ Link from Gremsy: DAMPING EXTENSION - Gremsy ←
→ Link from Airsupply: gPort Damping Extension | For DJI Drones | Accessories | - Air-Supply ←
Here it is on the M300 with the Version 1 - R2A NSA
Get one!