I am using a TS-253A successfully for my Sooloos system, with 4GB of RAM. However, it would not work at all (for Sooloos) on QNAP firmware 4.2.1 and I found it unreliable on 4.2.2 (which I believe is still the latest). Reverting to firmware 4.2.0 has resolved all difficulties.

Cinema/Music: Trinnov Altitude32 8-16,218,Cloud 4 channel, Marantz UD5007,DSP5200SE(2+C),DSP3300(4),DSW(2),271,MShort Ceilings,AppleTV 4K
TV: Marantz SR7013 Wharfedale Diamond 9x4+Celestion(C)
Music: Roon,i7NUC8gen,QNAP TS253A, Sony Scala, MS200, Garrard DDQ650,Wharfedale Diamond 12.3
Kitchen: AD88 (bluetooth via i80).