You can control the mtext line spacing 'exactly' now, you know.
You can try, but it doesn't always work. See the response I got back from AutoDesk:
As per what I have communicated to you few days back, I could reproduce the discrepancies you
pointed out. I am logging the 2nd and the 3rd issues which you have mentioned, with our development
team for further investigation.
For your first query, the value of TSPACETYPE does not change with the files.
You will be able to have the changed value of the variable applicable to the other files too.
However, if other files (having the different TSPACETYPE value than the last changed one) are still
open, they will be temporarily showing the older value contained in the file. Once they are closed
and reopened, the last changed TSPACETYPE value will be applied even to those files.
Regarding the 2nd query, that whenever the multiline text is copied from some text editor and pasted
in AutoCAD (keeping TSPACETYPE value as 2), the copied MTEXT behaves as having default value of 1.
TSPACETYPE behaves in the similar way when the TEXT is converted to MTEXT, as per your 3rd query.