Help identifying some decomposers that showed up in my composter

I have some new helpers that showed up in my composter. They look like some kind of insect larva, but not like a typical maggot. I wonder if they could be soldier fly?

I'm hoping to find out if they're beneficial, in which case I may encourage them, or even transplant some to other places I could use them, or detrimental, in which case I may try to remove them or at least keep them confined.

The top picture looks like soldier fly larvae (on mobile so can't see the bottom picture very well).
If they are BSF larvae, you should expect more to show up soon, as long as you keep them well-fed