Converting an avatar to quest can be done with the following tool: https://github.com/kurotu/VRCQuestTools?tab=readme-ov-file
Add a Repository in VRCC, then put in the following link: https://kurotu.github.io/vpm-repos/vpm.json
Follow the instructions in Activate a Package to make the package available in your current project. Once done, you will now have the ability to right click an avatar’s root to convert it to quest.
Check out Reduce Number of Physbones for information on how you can squeeze in more dynamics.