Die war bei mir gestern mit CM 12.1 vergleichbar, gefühlt sogar etwas besser. Ich werde heute Abend noch einmal berichten.
New M build is up: crdroid-6.0.0-20151121-jfltexx.zip
crdroid-6.0.0-20151121-jfltexx.zip | by jejecule for Galaxy S4
Changelog: see attached or in device settings/about phone/about crdroid
Please don't flash this rom if you want a stable one, you still have last crdroid 5.1.1 for that.
External sdcard: I had some time to look into it. In fact it's not really a bug. M has implemented a feature that allow you to use your external sd as internal storage. When you boot for the first time it ask you to format the card, then give you two options, or use it as before (portable storage) or use it as internal storage. The "bug" is that formatting via the device does not work well.
Backup your file on your pc. Format your card still via pc (fat 32 is good). Mini partition tool is working quiet nicely for that for Windows users, Gparted for linux ones.
Then insert you sd card and boot the device, it will recognize a new sd and ask how you want to use it. That's all.
RIL issue: please test and report.
Cheers & Nice weekend