I have just configured an SD Card with (what I believe to be the latest) ZX Spectrum core (Release 20170712) for my MiST.
Everything seems to work quite well, except that the behavior of the "Fast tape load" seems erratic.
If it's ON, it will just load the game almost instantly (as expected), but if I turn it OFF the behavior is the same. No 3-4 minutes "slow loading" with the nostalgic colored sidebar stripes or ear bleeding noises ...
I understand I sound like a masochist, but as we all know around here, authenticity is important (or I would not be using a MiST).
Here are my other configured options for your reference:
Video Timmings: ULA-48
Scandoubler Fx: CRT 50%
Memory: Standard 128K
Features: ULA+ & Timex
Does anyone know if this is a bug, or if I'm doing something wrong?