Read configuration of a VAF and Metadata Card

You're on the right track.  You work for a partner?  If so then take a look at page 19 on this document: GPC 2023 - Developer Track content.pdf

Thanks, this helped, we now have a working prototype to save AVS, MDC/MCC and the config of the VA to M-Files.
We were wondering if there is any way to access configs of other Vault Applications (in the same vault).

In GetRegisteredConfigurationDomains(ConfigurationDomainType.Other) on index [0] we find the current VA, are there other ConfigurationDomains or anything else I'm missing?

From recollection there is nothing here which stops that, provided you have access to NVS.  I know that external applications have used this approach to enumerate data for various purposes.  I don't have further samples than that developer track PDF though.

However: acknowledge that this is not something which other applications expect you to read or edit.  There may be some concerns with you doing so (e.g. secrets).