If you are familiar with networking on Linux and routers, you might get a kick out of NetThrottle. Configure everything under the sun, from Wifi Supplicant Scan Intervals, watchdog timeouts and retry counts, NetStats and quota controls, TCP window sizes, and even location throttle intervals.
Note that this app requires the WRITE_SECURE_SETTINGS permission that can be granted with EITHER a PC using ADB or root. Root is NOT required for this app, it is optional. Android 8.0+ is supported, with more features enabled on Android 10+.
Uninstalling the app will not reset the configurations.
This project is FOSS in the sense that the source code is freely available at https://www.github.com/tytydraco/NetThrottle. It can be compiled using Android Studio Canary at your convenience. While I offer support for the app, I cannot help you compile the app from source.