When it comes to open source software I would:
1. Modularize the code to allow plugins so users can start using them immediately, and you can vet them at your own pace. 2. Make tests robust and easy to run (one command to run, at most one to setup) so you don't have to pore over their code to have some confidence that it works.
This is the real key - modularize, pluginize, or otherwise make it so features can exist behind an "experimental" tag or similar, so that they can get merged and out there and not disrupt users if something doesn't work or goes wrong.
Actual Budget uses this well and merges PRs much faster, because they have the "it's experimental" to hide behind.