For me there isn’t really a debate here, the standing is quite clear.
What I’m trying to understand from your side, based on this statement…
…is whether the challenge is that you’ve built development work around a development branch, and now the timeline doesn’t align with your expectations. Victron generally doesn’t publish timelines for betas, so it’s tricky to make commitments based on what might be assumed.
If this is truly for a critical system, then the recommendation in the guides is to use the official releases. By definition, a critical system should avoid surprises, while development branches can and will shift unexpectedly. As we have just experienced - an unexpected shift. I don’t have all my betas on auto update so it is possible to avoid the unexpected changes.
I think that’s also why there isn’t a permanent repository for betas in the same way there is for releases — the idea is to keep betas moving forward, not to encourage long-term reliance on interim builds. (Which can also be scrapped entirely)
As MikeD mentioned, 3.7 is currently on hold while other priorities are dealt with. Even if you had kept a copy of the beta, there’s every chance that by the time development returns to 3.7 it will have changed significantly, which could make earlier work unstable anyway.
So for now it is just be a matter of “please wait” — while keeping development on betas for testing purposes.