Every time I go to a different brand, it changes back to 50.
Is there a way to change the default?
Yep you sure can! Go to All settings & Tools > Advanced Configuration
Search for a name of CPANEL_DEFAULT_ITEMS_PER_PAGE and set it to what you want. This will apply to all sections of the control panel.
The maximum number per page can also be overridden here with CPANEL_MAX_ITEMS_PER_PAGE
Just be aware that showing more items will slow down the control panel page loads.
Weird, it works for me. I set CPANEL_DEFAULT_ITEMS_PER_PAGE to 200, then went to Products > View products and by default it's showing 200 per page.
CPANEL_MAX_ITEMS_PER_PAGE just configures the maximum you can set "# Per Page" to. By default this is 250, so if you try and set "# Per Page" higher than that in the control panel it just forces it back to 250. I'd be careful messing with this, you could make the control panel very slow and cause timeouts.
Hm I don't think so, it was instant for me both times I tried. The control panel shouldn't be cached. Double check that CPANEL_DEFAULT_ITEMS_PER_PAGE has changed.