Command like updaterender but for all modified areas

[Coosanta17]

Feature Description: This is quite a niche area, but I would like a command like updaterender that only changes updated tiles BUT it does it for every updated area in the world. Currently the updaterender command scans the neighbouring tiles around the localised area the command was run until there are no more updated tiles to render, but doesn't check if tiles need to be updated elsewhere.

This new feature is for people who have low-end server resources that wish to render all updates at once during a low activity period or something without the need to fullrender.

Additional context: I don't know how updaterender works, but maybe the "needs update" check can be used on every tile in the map instead of neighbouring ones only.

If that isn't possible as a complex solution, it can use the property that each chunk has a "LastUpdate" time variable stored. Dynmap can store the last update time for the chunks it renders, and when the "fullupdaterender" command is run, it iterates over all the chunks in the world and compares LastUpdate time. It will be much less resource and time intensive than a fullrender. LastUpdate shown in the region mca file at a chunk:

I am happy to code this myself (and pr) however due to my current workload it may take a few months or years. Just putting this issue out there.