This is probably a bug…
I have two files which started out as the same file. In them are basically a small mesh and an armature.
Somehow one filesize is 4MB, whereas the other is 150MB.
The mesh has a hair particle system modifier, basically both the same.
In the large file if I delete the particle modifier and save, it reduces to 2MB.
Also if I append everything to a new file, the filesize drops to 4MB. So the extra data is not brought with it.
*** I may have had a play with Dynamics in the second file (but think I did this whilst everything was still the original file), yet any bakes were deleted (and i’ve been back, enabled, rebaked and redeleted)
Now, I don’t mind just deleting and adding a new modifier, but its making me wonder…