Flint 2 (GL-MT6000 ) - bug reports - collective thread

Nah.
Snapshot is called snapshot because it’s exactly what it is: An automatic generated snapshot of the current code base. Nightly would be the same.

Which firmware flavor for what?

Firmware flavor Usage
Stable Latest version that has been released for operation and has been sufficiently tested.
RC “Release Candidate” - A beta firmware that will soon be labeled as “stable”. As a rule, no major problems are to be expected.
Beta Newer version that has not yet been fully tested. Use at your own risk!
Snapshot Also called “nightly” or “testing”: Is generated every night from the current source code and therefore contains the latest changes (but also a lot of bugs). Use at your own risk and generally not recommended!
Clean Firmware without GL.iNet addons - corresponds more to an original OpenWrt firmware
Tor This firmware has Tor installed by default, this feature is in beta. Use at your own risk!

See How to get support quickly