You cannot change the display time in PSE 2022. The only way to change the timing is to use a different template. If you need more control over your slideshow, you need to use Premiere Elements and create your slideshow manually. As you may know, older versions of Elements had a different slideshow creator. If you still wish to use that older version to create slideshows, there is no problem in having more than one version of Elements on your computer. They are entirely independent of each other.