Hello,

I don't think that it is possible.
If it is, the information is interesting.

However, this poses a problem of consistency for the graphical interface and therefore the user.

Your need can probably be managed differently.
As you mention, you can add information in invisible columns or add a second invisible table too.
If you want to add a line directly after another you can use the "Insa" instruction.
If a line should disappear, you can use "Dela".
If a line should not be changed, you can play with the field action "before entry".

I don't see any other leads right away but I could be wrong.

Anyone have another idea ?