Is the partner copying the course within the same Learn instance or into a different Learn instance? Is the module described a system wide globally configured module or a local one added by an instructor in that one course?
I'm speculating here but although you have used the word "limitation" to describe this I would argue that it would actually be highly undesirable for consumer key and secrets to be copied as part of a course export or archive. The fact that they are a "key" and "secret" is about a security aspect and therefore I would almost be surprised if they did copy over.
This may not help your use case but would be my default thinking.
I believe that this is one of the key issues we've encountered with the stock Bb LTI integrations. We have an extensive master course library, and often have custom parameters configured within our master courses for LTI integrations that will need to be copied out to the "live" courses (things like eText references, where we have a global key/secret, but use custom params to identify which book).
I'd highly recommend that you take a look at Stephen Vickers' Basic LTI (SPV Software Products: BasicLTI Building Block ) building block, which addresses this exact use case.
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