Ksyxis Mod 1.16.5 will allow you to speed up your world loading by not loading nearby chunks every time. It may be incompatible with some mods.

Note! It is not stable at some points.
How it operates
Vanilla Minecraft loads 21×21 (441) chunks each time you load a world. The present mod will disable that feature.
If it does not work, it means that the effect may not be noticeable on high-end PCs. It’s a design mainly for low-end devices.
Remember that some Forge versions will need you to install additional mods. So, it can run in the Mixin environment.
Ksyxis is a miscellaneous mod as well as a server utility.
Requires
- Minecraft Forge
Screenshots
Minecraft Mod 1.16.5