or is there a way to bypass these user strings and instead go by screen size? For example, any screen less than 500px wide is considered mobile.
No it wont cover all mobile phones. Some browsers don’t identify that way. There is a default set of strings when you install plugin organizer that should cover most mobile browsers.
Plugin Organizer is not programmed to identify the screen size. That is a client side process that happens after the page load and can change during the session without reloading the page.
The reason I ask is that I have another plugin called Device Theme Switcher which serves a different theme for mobile and desktop. I want Plugin Organizer to be synced with it.
When I spoke to the creator of that plugin he told me they use something called MobileESP library: https://github.com/ahand/mobileesp
And that the list of strings can be obtained here: https://github.com/ahand/mobileesp/raw/master/MobileESP_UA-Test-Strings/MobileESP%20UA%20Test%20Strings.xlsx
But when I looked at the UA strings they look very long and include browser versions. Can you please take a look at it and tell me if I can paste all those strings into Plugin Organizer? Thanks