Make changes on a ppd in Ubuntu snap cups

In Ubuntu, how do I modify a ppd file? Ich chose a driver which doesn't 100% match my printer model and tried to do some modifications on it.

The file is located at /var/snap/cups/common/etc/cups/ppd/myoki.ppd.

But without restarting anything, the changes don't have an effect. When trying to open a print dialog from an application, the changes are not visible.

After a while, I found the following commands useful for restarting cups:

sudo systemctl stop cupssudo systemctl stop cups-browsedsudo killall cupsd cups-proxydsudo systemctl start cupssudo systemctl start cups-browsed

But after restarting, my ppd file is reverted to what was there before my modification!What do I have to do so that my changes are recognized my cups?