MyGica T230 is working without any problems (HD51, latest OpenPLI). I'm use this stick in DVB-T/T2 mode, no problems at all.
You need to install drivers in telnet, with opkg install command (for example: opkg install kernel-module-dvb-usb-cxusb).
For T230 You need these modules:
kernel-module-dvb-usb-cxusb
firmware-dvb-fe-si2168
kernel-module-si2157
kernel-module-si2168
After drivers install in telnet You need to change one file in /lib/firmware directory (faulty file is dvb-demod-si2168-b40-01.fw). If You don't replace this file tuner detects t230 stick but no picture. I found working dvb-demod-si2168-b40-01.fw file in openHDF image and replaced working file in pli and now this stick is working. Uploaded correct file here: https://www.upload.e...-b40-01.fw.html
NB! Stick is working only in USB 3.0 port and restart is required!
DVBSky T330 is also working behind HD51 but simillar problems in PLI. Some fw files is faulty and You need to change these manually (you find working files in OpenHDF image, directoryes /lib/firmware and if these are not enoughy then look /lib/modules/4.7.4/kernel/drivers/media). I can't test t330 at the moment because it's now used in different location behind vu+ zero.