I uploaded "propeller mount 16_19".
It makes no sense to make the mount stronger.
If you give more than 600 grams thrust it is more likely that you will sink it.
The high positioned motor will push the bow downwards and the more weight reduces the tipping stability.
Have fun - but with caution.
BTW, I only need 1 kg thrust to fly my heavy 2.3 kg printed plane with 2 meter wingspan.