As far as I'm aware, except for a little tweaking for conventional DC operation, the SD70 and ES44 code is the same. Electric Railroad Company did the DCC development for Lionel back in 2012, but Lionel ended their contract and they have also now exited the business.
Looking back, using the programming track for Lionel/Flyer was erratic, while PoM was fine. One thing I had to do with my MRC system (even with the 10 amp power supply) was purchase a booster for the programming track. This one is from DCC Specialties purchased from Tony's Train Exchange.