Caspar and premultiple in BlackMagic ATEM 2ME

i use Caspar with BlackMagic 4K Extreme card with my video mixer ATEM 2ME 4K. When I configure my mixer and set "premultiple", my lower third look like very nice but on full screen has opacity about 80% - it means I can see what is on lower layer (image from camera).
When I switch off "premultiple", than photo on full screen has 100% quality but lower thirds is in a very poor quality.
Is any way to have very nice lower thirds and photo on full screen without switching on/off "premultiple" function?