No doubt a paved runway would help with the legs "as is", but here's the nasty thing: that nose leg suspension ain't right.
The swingarm in extended position is near vertical, while the cantilever acting on the vertical spring is near horizontal.
Now when the plane rolls, due to this setup, the slightest bump will push the wheel backwards, compressing the spring.
This will bring the swingarm towards horizontal, but the cantilever towards vertical. This changes the springing geometry such, that the springforce is regressive instead of progressive. The further the suspension is compressed, the lower the returning force becomes.I tested this with weights, and at a given additional weight that will NOT compress the extended spring, when the nose is pushed down the spring will not return.

So when the plane rolls down the runway, the suspension compresses but won't come back.
For the maiden I improvised with a few tie-raps around the plunger, but that basically limited the spring travel "hard", which resulted in a bad landing.
So now I put a few O-rings around the spring plunger, that add a bump of additional springforce about halfway through the travel, and that should cure the issue.