Here's some feedback from a first partner (thanks to Dominik):
We haven't had any issues with this so far. However, since we also build our own applications (Java backend, frontend, etc.) and host them on SAP Cloud infrastructure, we probably don’t run into this problem.
Given that the SAP world has what feels like an endless number of tools/products/etc., it’s hard to make a blanket statement like “SAP has a character limit.”
It’s quite possible that this is a restriction in some legacy version of an ancient SAP RECC system… (or even in one of the newer SAP products).
I don’t know the specific circumstances, but we’ve had cases where the SAP user interface didn’t allow certain things—even though they were technically possible (e.g., displaying more than 100 items in a dropdown, despite more than 100 items existing).
If it really is a limitation in the SAP system standard, then the chances for a workaround are usually slim. I also see little chance of success for a change request to SAP.
If the issue happens to relate to use cases on SAP Business Technology Platform, SAP Cloud Platform Integration, or SAP Sales Cloud, we might be able to provide more insight.