Bug in setting more than 16 hidden transaction item columns in work order

This one is really confounding me... I have 23 custom columns configured in a custom Work Order form (set as preferred). They are all configured as not visible. When my suitescript runs on the work order, I attempt to set all 23 at once and I can confirm that my 'setLineItemValue' function is firing all 23 times with the correct column id and value. However, only 16 get set according to the work order sub-item history, and they are the same 16 every time.

Now, if I set ANY of those custom columns as visible in my custom Work Order form, all of a sudden I am able to set all 23 fields without issue, again as confirmed by inspecting the Work Order sub-item history. This is very weird that it doesn't matter which column I set as visible, just so long as one is visible at all, then I am able to set all 23 fields, whether the remaining 22 are visible or not.