Do I need to test applications for Windows 10 support on both LTSB and CBB?

I have a set of applications for which we want to add Windows 10 support. I expect some users to run them on Windows 10 Enterprise LTSB (Long Term Servicing Branch) and others on Windows Pro CBB (Current Business Branch). Sometimes our users keep machines off LANs for security reasons, so we can't assume much about when updates will be applied. We also can't dictate that our users get all Windows updates as a first step to troubleshooting. (It's a case-by-case basis.)

We have not historically needed to consider special editions of Windows. In the past we have tested these apps on Pro versions of Windows and Standard versions of Windows Server.

I'd like to relate this question to precedents, but I don't see an obvious correlation. For example, would an LTSB vs CBB machine comparison be more like Windows XP SP1 vs Windows XP SP2 (which was a breaking difference for us) or is it more like Windows 7 Pro vs Windows 7 Ultimate (which is insignificant for us)?

I did not see any distinctions between LTSB and CBB in Windows SDK googling and we don't expect to depend on any of the Windows apps currently excluded from LTSB. I think the main issue is whether there might be windows behavior that is changed in a "Feature Upgrade" that a CBB machine might get and an LTSB machine might not yet have. (As opposed to a "Service Update" that I hope they would both get, if receiving updates automatically.)