Huh, interesting. Didn't know that was a thing - I guess you learn something new every day. Seems like this is an issue for all my models. Will look into optimizing. Already did a bit:
UPDATE: Thanks to
@Stefan.K I noticed a large number of scaling keyframes that are unnecessary. Optimized the model by removing these keyframes.
UPDATE 2: Managed to optimize even further by removing position/translation keys as well... I should probably do this for all my models