how to hide a column or set a width of zero in Numbers

I'm trying to convert my MS Office 2011 Excel spreadsheets to Numbers so I can upgrade my OS from Mojave. They're large and complicated but if I can get them to run under Numbers I will give up my 30-year relationship with Excel.

One thing I use is columns of zero width (hides the column completely, but of course retains the data and can be expanded when needed). I also have a number of columns where I've used a column width of .005 (this collapses the column but leaves a vertical line indicating it's there).

When opening these Excel ss's with Numbers, the zero-width columns come thru as zero width, so obviously the program will support that; however, the .005 columns have been expanded to 9 points, which is useless, but I'd be happy to just forget the .005's and reduce them to zero if I want to hide them, but I can't. The Table/Row&Column Size menu will not accept a zero or any value less than 9.

How do I either hide the column or force a 1-point column width? (no help from Apple Help)