you are in the situation I was in -- did not update my BDP-1 for years.
I updated to Moose earlier this spring. It's worth it imho. No glitches yet for me, although I'm not sure what gains were there in Moose, as I don't fuss over cover art, Tidal, Roon, etc. It's about the music for me.
I still use MPad on my tablet, no updating either. Works fine, as does the Bryston BDP site thru browser. That one's nicer, and displays cover art for many of my albums, unlike MPad.
Once you update MPad, I don't believe there's going back if you are p---ed at the update, so user beware maybe?