I followed this website: https://www.retrorgb.com/snesverticalline.html to have my SNES' 7805 regulator replaced with a 78S05 which should take care of the annoying vertical line many SNES' experience.
Before mod:

After mod:

As you can see the mod did work to solve the vertical line issue, however, I am noticing more pronounced jailbars. I decided to add a 22uF capacitor as mentioned in the link, however, I am not sure it made any difference because I still see the same result. It seems to be noticeable on greyish or dark-blueish backgrounds though.
My snes is an SNES CPU-GPM-02 and I am using S-Video exclusively, also, I am not really interested in using RGB. Is there any mod or known workaround to minimize or solve the jailbar issue?
This is perhaps something simple since I have seen some people putting copper tape on their NES' PPU to take care of jailbar noise, same for Genesis V1.