DSP with MQA and Meridian

No. Once the folded MQA stream is altered, it is no longer decodable.

Correct. I would lobby Meridian to get this fixed, which is what I have done (on a personal level). We need firmware for all of Meridian’s products (818v3, 808v6, 218, Explorer², Prime?) which fixes rendering of previously decoded MQA (with intact signalling information, as Roon provides, and other rendering devices are capable of using).