Code review comment for ppa-dev-tools:packaging-snaps

     source: https://git.launchpad.net/ppa-dev-tools
     source-type: git

That is great to e.g. CI build.
But AFAIU this will build from there even with different local content.
It might be what you want and you can keep it.
But if you commit something locally and run snapcraft it will not have this new content until pushed.

While it is a bit low-tech, for me
   source: .
behaved often more how I liked it.

Entirely up to you as it depends on how you wanted to build things regularly.