Is There a Limit on the Number of Content Types Allowed in a Library?

We got in touch with Microsoft support. Apparently this is a known issue. There is a limit to the amount of columns that can be fetched at one time. Every column type has a different impact to that maximum. So I think this isn't directly linked to the number of content types, but rather the total columns across all content types in a library...even if you use the same columns in all the content types. Had to consolidate some content types into broader categories....and then relied on a managed metadata 'document type' column rather than classify our docs using content types.