Thanks for all your replys. This weekend conditions were epic in the Netherlands, unreal waves!
I adjusted the front strap, making it one screwhole less wide and at the front side I narrowed it to the second mounting hole. Now my toes are not rubbing to the inner webbing any more.
I took my 7m and had the best session of this year, without pain in my toes
The straps remain to be poor quality... When leaving the beach a fellow surfer mentioned the Dakine straps to me, which looked and felt very fine and I immediately bought
So, thats it... I'm happy again