+1 for these Cat6a cables from Universal Networks. Very good customer service as well.
I used them to replace all my ethernet cables and the SpeakerLink cables, not for sound quality but more flexibility in choice for lengths. Soundwise it sounded better than my coiled up 10 mtr SpeakerLink which was an unexpected bonus.

I would not expect a difference in SQ between MC200 and a QNAP, the endpoint makes the difference. Connection MC200 directly to DSP is a nice minimalist solution but not delivering the best SQ.

Some people reported SQ improvement by replacing the wallwarts used on the network devices, in case you have some further urge to tweak.

Cheers,

Living room: Ansuz Mainz8 C2, Uptone Ethernet Regen, Grimm MU1, Audionote (UK) DAC 5 Special, TT2, M2RIAA, Audionote (UK) OTO Line SE Signature, Fleetwood Deville SQ
sold (Q1-2024): 818v3, DSP7200SE
Office: MS200, audio engine A2+
Spare: STAX SRM-323II, SR303, MC200 (Roon ROCK’ed),
Roon: life time subscription