Let's say, we had LMA (License Managing Application) configured for our managed package and subscriber granted us permission to log in on their behalf via Subscriber Support tab.
If we logged in, would we be able to see on subscriber's org all protected custom settings and custom metadata hidden from subscriber by managed package? Would we be able to update them, i.e. custom settings values and custom metadata records? And what about introducing new fields to protected entities right on subscriber org?
If so, could we use this 'Subscriber Support' feature not just for debugging purposes, but for doing some additional/special configuration on subscriber's org? E.g. we are delivering managed package using 'generic' external service as a default, but for some VIP clients based on request we may log in via Subscriber Support and update endpoint/credentials/keys in protected settings to switch to 'Premium' external service (at the same time not exposing any secret info to VIP clients).
Any help would be appreciated.