I was able to do this using S 12 Plus. It's a little tricky, but it will work.
I did it using some text I typed in the overlay title.
Make the title, copy it to the overlay track. I made the font on the overlay track yellow and that in the title track white.
Use the 'Blurr' effect on the overlay track to diffuse the text.
Apply PIP to the 'title' track.
Using keyframe and the cropping function in PIP, set key frame one for all the text to be cropped and keyframe two for all the text to be visible.
As you play the clip, the text will become visible as though it were wiped on. If you have more than one line of text, you will have to repeat this for each line.
The new way that PIP cropping works in S 12 makes this sort of thing very difficult to perform. Like I said, tricky but possible.
Don