We've been puzzling over how folks use those settings and asked for more info at Collect server settings screen: remove 'Other' server type and replace 'ODK Aggregate' with 'ODK'. Thanks for solving one mystery, @J_D1, we didn't consider that folks might be using query parameters instead of resource routes for things like projects.
About half a percent of Collect users set custom endpoints and the "Other" server type has caused confusion in the past. I think that by moving the endpoint configuration to the main server configuration screen and making it clear most users don't need to touch it, we've largely addressed the confusion. If we do remove the setting, we'd give 6 months to a year of notice. In the mean time, it's helpful to hear about what users put there.
Do you control the custom server you're working with? Could you consider introducing a route that looks like /projects/projectid/formList?