Mod name: TipTheScales
Modpack: Mythic: Novus
Link to mod download page (must be CurseForge): https://www.curseforge.com/minecraft/mc-mods/tipthescales
Reason it should be whitelisted: Client-only mod that allows for finer adjustment of resolution.
Additional info: I have a big 40" monitor with large resolution. My choices without this mod are either tiny or huge GUIs.