The chair goes from 316 tris to 832 tris
Tools Used:
Blender 2.93 - Modelling program that I used to make the chair's seat higher poly, I used an older version because newer versions don't import nif and their collision's for me, hell even this version has some issues
Blender Niftools - Community addon for Blender that adds support for Bethesda file formats such as NIF and KF
Nifskope 1.1.3 - Specialised tool for NIF models, used to workaround Blender's lack of support for collision meshes by pretty much swapping the vanilla mesh with mine through this program
Weapon creation tutorial - Optional 3 (Fallout: New Vegas conversion) by Millenia - An old tutorial by Millenia with information on how to mesh swap using Nifskope, has some other quite useful info relating to modding that will be difficult to find without asking modders directly, so thank you Millenia!