Black Soldier Fly larvae waste

So BSFL have been touted as being almost scary good at reducing waste, maybe even better than regular earthworms, but I've never heard mention of how their waste matches up to worm castings. Has anyone had a BSFL bin that could tell me what the left overs are like?

I've heard a bit about how the redworms that people buy for vermicompost might be an issue as in mildly invasive, but as far as I know that angle hasn't been explored. I'm trying to start up a bin wiht natural worms because I'm too cheap to pay for them, but BSFL could be another alternative,  I just want to know what I'm getting myself into.

I guess that depends on what they eat.

I remembered watched a youtube somewhere that people feed coffee grounds to BSFL and the waste came out dry and granular like worm casting and was ready to use as fertilizer.  Sorry I don't  have the link.

I feed food scraps to BSFL and the waste is greyish-beige in color and has a sticky glue texture. I mixed it in hot compost pile and ground around the pile got tons of worms. I plan on using the waste in seed balls, 1)to provide fertility and 2)to hold the clay ball up longer with its sticky nature.