Perhaps you could have ESU make a non-select version of the Cab Forward. If you want someone else to join you in making the request, let me know. My MTH PS-1 equipped RailKing Cab Forward is in my queue for DCC conversion and I was concerned that they only had the sounds for Select decoders.
Just to follow up, I made a request at the ESU website:
Topic: L/XL Conversion for sound project 74409
Would it be possible for you to make conversions to project 74409 (V4.0 version for Cab Forward) so that it supports smoke and any other features of the LokSound L/XL V4.0 decoder? There are several of us who would like to use it in the O gauge community.
I will post if I get a response.