Testing Bachmann 36-567 with ESU 53900 DCC Decoder Tester

Hi, I've just bought two Bachmann 36-567 Next 18 DCC decoders for evaluation as it has Zimo features and has four function outputs and four logic level outputs. I bought an ESU 53900 DCC decoder tester which includes a Next 18 Socket but the online manual says the 21MTC FO3,FO4,FO5,FO6 are at logic level. The 36-567 also has FO5 and FO6 on the Speaker outputs of the Next18 socket - which shouldn't cause damage as the speaker on board the tester can be switched out of circuit.

I think the problem is the confusion (and lack of clear labelling) which separates Next18 and Next18S. The former has the eight function outputs, the latter has six function outputs and two speaker outputs. Both of these standards mandate a space for the decoder, the "S" version mandates more space to accommodate the sound decoder. See the MOROP website for the standards document NEM622 (German and French). I've not read enough of these to see if the standard requires that a NEXT18 decode