[Mossie]

A very interesting discovery.

I built a complex structure and a set of three oval tubes to use for cutting.

At 0.1 m scale it left a large number of anomalies
At 256% scale, it left a smaller number of anomalies
Increasing scale another 256% resulted in no anomalies.

So what happened if I scaled it to 1%, AC3D crashed.

You may well be on to something. A flaw or overflow of the maths.

Would be interesting to hear what Andy has to say about this.

Booleans have always been a bit hit and miss.