https://mods.factorio.com/mod/BeltSpeedMultiplier
I tried to use this mod so Mini-loader speed could be equal to changed belt speed but your mod not allows this tuning
Is this inner options of your mod so speed cannot be changed or its bug?

The miniloaders pick up the speed from the belt prototypes. If that mod runs after the miniloader mod, the speeds would be off.

There are many mods out there that modify speeds, stack sizes, offer new belt tiers etc and it is not possible to support everything.

I deeply regret to have ever opened that Pandora's box of supporting other mods and I will not actively add new tiers / mod support / speed modification myself.

I am willing to review PRs / test changes that seem reasonable but I will not go out and test or support every mod that exists.