Both our infrastructure and our application code has changed drastically since that time period with a strong emphasis on performance. I would dare say ingesting your turnovers should be fine.
One thing to keep in mind is that if you add fields on entities, these new fields aren’t indexed by default in the database. This isn’t done automatically because we don’t know if these new fields will be used in filters and indexing has a database cost associated to it which makes indexing everything counter-productive.
This could lead to some read performance issues if you have a lot of custom fields and these are used heavily in filtering, grouping and/or sorting. If you do experience this I suggest you contact support so we can profile your data and requests and see if we can implement some mitigation measures in line with your data and query profiles.