About config files:
Different phones may need different settings. Some GCam versions support
.xml config files, allowing users to quickly import (load) and export settings.
If GCam doesn't work well on your phone, you may want to try one of these configs created by the community (read: How to Import/Export .xml files).
If more than one config is available, try the first one. If you're not happy, try the second one (and so on). There's no need to try them all.
HTC U Ultra »
Realme 2 Pro »
Realme 3 Pro »
Realme 5 Pro »
Realme XT »
Samsung Galaxy S8, Note 8, S9, Note 9, S10, Note 10 (+variants // Snapdragon) »
Xiaomi Poco F1 »
Xiaomi Mi 8 Lite »
Xiaomi Mi 9 »
Xiaomi Mi A2 »
Xiaomi Redmi K20 Pro/Mi 9T Pro »
Xiaomi Redmi Note 6 Pro »
You can configure the app manually. Disable the settings/features that don't work on your phone. If you need help, find a forum thread and ask which settings are better for your phone (see my list of useful threads/groups).