Feature: NewGRF callback profiling #7868
Just extra info...
Filesize: 30 days of Horse profiling (in a small game) gives 3m line csv. Some Excel versions, Apple Numbers etc won't open large files (the limit is sometimes 65k). Libre Office, some Excel versions might do more. I'm thinking that grf authors will find it better to write a python script to summarise the data, or maybe a jupyter notebook or similar.
…and local id to output
…ent GRF feature for generic callbacks
I think most NML GRFs will have automatically assigned item id's, but it really ought to be the value you can use to figure out which specific engine, industry tile, or whatever, that's causing the activity.