Currently, there is no enforced hard cap on the maximum size of a single markdown file.
However, as a markdown file gets larger, different problems start to become apparent.
There are performance slowdowns first, likely due to the indexing process struggling to parse the file.
The automatic savings strategy, along with file recovery snapshots and syncing frequency should also be fine tuned for these cases.
Beyond a certain point, large files can cause OOM problems, especially on mobile.