I have a similar mod Schall Belt Configuration allowing editing speed of all transport belts. I am not sure what will happen if both mods are installed, due to double modification of belt speed.
Inserter speed is new to me though. At least I have never touched that.

If both mods base their belt speed on the game's raw belt speed, then the belt speed will be multiplied twice. I didn't realize there was a mod similar to this one; I apologize if this seems like copying your mod. That was not my intention.

It's alright. It's tested and confirmed that your code is applied after mine. So double modification like you said.

By the way, the reason why I added an option to increase inserter speed is because if the belts get too fast, the inserters won't be able to keep up. It's a way of scaling both types of logistic tools so they can still be compatible with each other.

Some experienced modders report there is some limit in inserter speed, due to the animation.
I have not tested that myself, since I use loaders instead for very high speed. Scaled up machines (from my another mod) or Bob's machine which has 60 crafting/second, cannot be handled by a single inserter.
But I understand for those who prefer to use bots instead of belts, it can be more convenient to use inserters.