@altruistictrog Hi mate, I'm interested in your work on the RetroCRT image. I always look out for new configs and solutions (use Pi2SCART myself). Is there any contact with you outside this forum (email, reddit or something) ?
We don't support third party images here and we definitely don't condone distributing RetroPie with pirated material in any way. That kind of activity is illegal and threatens the very existence of this and similar projects. Accordingly, the @Wolfanoz account has been banned.
Right, I've heard that Linux people can bypass the Emudriver.
But still - did you try Retroarch standalone? The latest one supports 15khz natively on Linux as well.
On RaspberryPi you need to change hdmi_timings in boot/config.txt to output to a CRT - not sure, perhaps directly from Linux on a PC it's different.