BBB moving from angstrom to debian 8.x | differences between debian versions

Hello there,
i’m currently trying to port our existing system from angstrom to the newest debian.
After some initial struggles I got everything up and running on debian lxqt version.
After playing around with it i realized I don’t need a whole bunch of packages preinstalled on lxqt version from http://elinux.org/Beagleboard:BeagleBoneBlack_Debian.

I mainly need c++/java/(node) running on the system, so I decided to go with debian console version and install the missing packages.

This works fine for most of the packages, but it seems like I can’t get the device overlays to work like they do in lxqt:
We use “/dev/mem” with mmap in our code, so I have to setup the device overlays correctly… What I did is:

uncomment: dtb=am335x-boneblack-emmc-overlay.dtb
add: cape_enable=bone_capemgr.enable_partno=BB-UART1
in uEnv.txt

git clone https://github.com/beagleboard/bb.org-overlays overlays
cd overlays
sh ./dtc-overlay.sh
sh ./install.sh

Which passes without errors.
After a reboot /sys/(…)/slots holds the entries for BB-UART1 like it does in the lxqt version, but it seems like there’s sth. else missing because I can’t get the c++lib to work like before.

Someone has a clue, what I’m missing here?
Is there a document somewhere which describes the differences between lxqt, console and iot?

Regards,
thx in advance!