Can I change delay between slideshow images on mate-screensaver?

[Huxley]

Linux Mint 19

Is there a way to change the duration of each slide? The default setting is 10 seconds, but I'd prefer it to be longer, say, 20 - 30 seconds.
The mate-screensaver gui doesn't have the option to adjust the duration, and I've also checked out the files below, with no success:

Code: Select all

/usr/share/applications/screensavers/personal-slideshow.deskto
/usr/share/applications/mate-screensaver-preferences.desktop 

I found this thread viewtopic.php?t=175994 in which one post suggests a process of installing xscreensaver with additional packages, uninstalling xscreensaver, then editing the remaining dotfiles, but that all seems very convoluted and messy.