I added Preview dialog. Also added some feedback as to current "arc" being processesed in the console window. Not all this released yet. Probably want to get notes onto progress bar rather than console window before long.
Other issues I had was did a boolean and thought it had progressed cleanly ... but there were tunnels between chunks because I did not reverse explode the chunks to overlap enough in first trial. So tunnels were unexpected and also created odd possibilities for TUBES.
Did a few other passes that didn't work so well (I was distracted by household goings on). But on last pass ... I decided to use Monodispres foam (uniform foam from ManifoldLab subdirectory of stuff) because this foam is nice and regular.
The final idea was to get less oddball sided edges from the Boolean union. You want the new edges to be more uniform and with less short edges and less tiny aces created. It takes some nuanced thinking.
I have a few more things to do to make it easier. I still have to break up the hard edge junctions as a separate step. It should be automatic in the furture.
I do insist in having a small instruction video because I still am not understanding the way... or, at least, give some step by step instruction... how do I chart an object first? : - )
There are many tools in ML that I do not know to use because I have been focused intensely on some of them only... so regarding the others I can be considered a total beginner... I do beg tolerance... : - )))