Should I use unity dll in .net core library ?

Hi all

I started to learn unity 4 months ago on my free time by developing a classic topdown rpg.
My solution contains the unity script project, and I choose to create an independant 'Rpg engine' .net core project.
The main goal is to separate two parts of the game: interface and engine.

I initially added the unity core library in my engine, but I'm now considering to get rid of it and use pure .net core code.
Unity dll is actually mainly used for vectors and bounds structures, which can be replace with points and rectangles .net core objects.

Before changing the code, I need some advice from advanced developers:
Is it a good approach ? Will it introduce some problems later on ? Or maybe performances problems ?
The goal is to avoid unity dll updates synchronization and have an independent .net library.

Does it makes any difference if I want to publish on android or mac/linux ?

Thanks

 

You answered your question right there.