With regard to the original poster's question. I also own a lot of MTH PS2-3 and am moving forward with a moderate sized layout to be wired for DCS. I have MTH 4000's, TIU's, and AIU's.
Recently I acquired 6 each Sunset 3rd rail locomotives (New York Central) all built between 2008 and 2016; all have a CONV/TMCC switch. Rather than ask the most cost effective I ask what is the best TMCC/Legacy equipment for me to purchase for command control of these 3rd rail locomotives and possibly any new Lionel acquistions?
John, With regard to variable channels on my TIU. I will be using both FIXED and both VARIABLE channels on one TIU. That TIU is connected to two Z4000 transformers. with 4 handles. I have been assuming I would be able to use all 4 channels both variable and fixed to run my conventional locomotives in conventional mode by just using the Z4000 handles. Should I want to use the DCS remote for conventional operations I could only use the variable channels. Are my assumptions correct?
.