is Lelantus just an implementation of Seraphis?

no

they are separate

From my point of view it qualifies as an implementation of Seraphis

Although there could be small disagreements between them

Lelantus-Spark*

Right, the Spark paper mentions you :D

UkoeHB: would Lelantus Spark also need a decoy selection algorithm or does it use a different method?

Yeah it does - I think Firo has their own approach to decoy selection

How many reused outputs did they decide to place in their bin? I forget

Not sure if that's the best way to describe the setup, so chances are it isn't

Don’t know

I am doing some testing. What might a reasonable implemented ring size be for the next generation of ring construction? A range would be nice.

64-256

Thanks!