Hello ,
I switched from linux receiver to tvheadend. In the past I used dvbapi to communicate between oscam server and client which worked perfectly. 
I turned on dvbapi  in the headend the tvh settings and after some tweaking it connects to oscam server which is the same device. 
tvheadend 4.1-1797~g2aa055d settings: 
OSCam new pc-nodmx (rev >= 10389)
/tmp/camd.socket
0
OSCam r11221 settings:
boxtype : pc-nodmx
pmt mode : 0
request mode 0 : 
au : 1
But zapping with this setting is nearly impossible , sometimes it takes 20 sec to watch a channel.
I can't see any issues in the debug file 
 If I'm using newcamd instead everything works fine.
Anyone using this kind of setup and will share experience?
best regards, sharky