Looking up the specs for that silent decoder shows the decoder has 4 outputs with an additional 2 "logic" outputs with the 21MTC connector version. Just what that "logic" refers to, can't say, but it doesn't say lighting outputs.
Function outputs: 4 outputs
21MTC connector version has two additional logic outputs
250mA load per output
500mA total load of all function outputs short-circuit-proof
Free function allocation (function mapping)
As Terry has "hinted", Scale trains has been not very forthcoming with information regarding the limitations of the Motherboard that is fitted in the DCC ready models they are making. The truth is, it is only functions fully with either the V4 or the new Locksound 5 versions. The "5", is the replacement for the now discontinued, US Loksound Select decoders. Considering that the DCC ready models don't have speakers factory installed either, what is the point of making motherboards capable of only functioning fully with sound equipped decoders. Even putting in a different brand of decoder, or the Lok Select (if you happened to have one) will you get all of the functions that decoder is capable of.