Hello @DeBi Thank you for reaching out to us on Microsoft Q&A platform. Sorry for the delayed response!
It's great to see you have done a good amount of research before posting your question on the community. Much appreciated!
As for your question, Capacity Reservation support in ASR is only applicable for Azure-to-Azure DR scenario. That said, the answer to your other question "Is this valid also for Hyper-V / Azure Stack HCI to Azure?" Is "NO".
Hope this helps!
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