I am particularly needy when it comes to the taskbar. I installed a few mods:

* Windhawk - can tweak taskbar with extensions similiar to gnome tweaks imo (free)

* DisplayFusion - qol for multi monitor setups (paid)

I would give it a try if these two applications help you, honestly there's just so many settings to explore -- but afaik static width was something I needed and got done through Windhawk.

You should not have to hack Explorer to make it usable.