> managing an open source codebase of this size would add real strain to our small team

Can you please elaborate what do you mean when you say this? This is something I do not understand. How licensing terms affect your codebase management beyond setting things up so the code is available to users?

Publishing something under a FLOSS license doesn’t mean anything except that you grant end-users certain rights (the four essential freedoms). The rest (like accepting patches or supporting external developers) is customary but by no means obligatory. You don’t have a capacity for it - don’t do it, easy. There are thousands of developers who do that - they just dump whatever they have under a nice license and that’s it.

Unless you’re saying your legal department doesn’t have capacity to handle licensing concerns, especially if you’re using or potentially using non-FLOSS third party components. That I can totally understand, it could be pretty gnarly.

Please don’t be mistaken: Free Software is a purely legal matter of what you allow users to do with your work - not some operating principles or way of organizing processes.

Note: All this said, I can understand that you may not want to grant some freedoms to the end users, particularly the freedom to redistribute copies, because this could affect your plans of selling the licenses. But that’d be a whole different story than codebase management concerns.