Loksound XL 3.5 and Massoth Buffer Cap

[Ger-Y-Nant]

I'm looking to upgrade an old LGB G-Scale loco (LGB21711) with MTS decoder to a shiny new Loksound XL 3.5 decoder.
It involves throwing out all the old electronics, so I'm looking for some advice before I take the plunge with the cutters...
I currently run the Loco with a Massoth Buffer capacitor, can I move this over to the XL? Do I actually need to?
If I can, where do I make the connections please?

Thanks,
Andy