Microsoft
MicrosoftHi Armine_Insight ,
I'm not a licensing specialist, although I did a fair bit of licensing in the past, so don't necessarily take this as a definitive answer. It's best to consult with a licensing specialist/partner here.
So to clarify here, the ISVs in question is also the SPLA reseller (they are not buying the licenses through another SPLA partner)?
The current use case indicates that it is the ISV's workload and not customer workloads, even though it is being used by their customers.
This means the ISV should license the workload as if it is their own. In SPLA the reseller is only allowed to license products for their own internal use for up to 50% of the reported usage of that product, so make sure they are still compliant there.
If I understand the use-case correctly the ISV is responsible for acquiring the ESUs since it is their infrastructure and their workloads. (Normally a customer using an ISV application doesn't care, or even know about the underlying OS or DB that the application is running on)
Again this is by no means confirmation that the customer will be compliant going this route, just my understanding of the scenario provided.
Feel free to pop me a message and I'll share my source and additional info if needed.