I am going to release an update to PDFToolkit, but found that the program looks broken in 4.1FE consoles.
I present the problem with a simple echo command in the shell.
Here is a picture from the UAE 3.1 installation (it is the same on 4.1 update 6, but I can't boot it now):

And here is the OS4.1FE result with the a same control codes:

You can see the the background color is rewritten from the first character in the row instead of just for the printed characters.
If it is an intended change, I have to find a workaround.
Can't found anything about the change.
Please let me know the reason of the new behaviour.
Thanks!