Why?
The past LagMap system was based on custom id generation. The issue with this is that it had to edit the config to set the MAP-ID value, which in turn removed all the comments (due to how the configuration system that spigot uses works). Due to the map setting process running on first start, it basically removed all the comments before you could even open the config file. Until now, i've had to resort to a temporary fix: Get a new map for every new time the plugin restarts. The issue is that there are only ~32k possible map ids you can use, and they would run out eventually.

The Fix
I've decided to set the map to function using the ID NR 0 and make it render normally if certain conditions making sure you should be able to see the map are met.
It detects when you change slots in your inventory and adds or removes you to the list depending on what item you are holding.

It's not as simple as before, but it's a good way of fixing the issue, and from my tests it is also lightweight.