Patience is a virtue, except we all want MQA today..
You can rest easy. As you might have expected from this team, MQA is hierarchical and extensible. The decoding architecture can fit perfectly into Surround Processors, Digital Loudspeakers and a number of other product types ...
I wonder if MQA will be offered as a firmware update for existing G Series kit.
As for the lifetime cost of Roon, being $499/£321, I would rather buy the physical QNAP kit on which to install the (free) MDMS Core.
QNAP (Amazon UK prices)...
TS-251 = £248 (as utilised by M at the Munich High End Audio Show), or,
TS-451 = £340 (4 Bay version of TS-251)