All of the shots in my gallery were done on Efke KB100, souped in Rodinal 1+50, at 20 deg. Celsius, between 10min 30sec and 11min, with tank inversion every minute. Took me a while to nail down those times to get the results I like - for scanning mostly. You might get a bit of grain, though, for "less than perfect" exposures
I think that D76 would be better for Efke films, but I find Rodinal much more practical - no powder mixing, shelf life concerns, etc...
I use Rodinal as one-shot developer.
(Edited about pushing
As for pushing it, I have no experience with that, but a guy on apug.org said he accidentaly exposed KB100 at EI400, thinking it was HP5... He developed it in Rodinal 1+50 at 20 deg. C (68F), for 20 minutes, and it came out fine.
I think I'll try it that way soon, just to see if it's usable.