Would it be completely unreasonable to allow fundrawtransaction to use unsafe outputs?
I understand this means the resulting transaction may be invalidated whenever the unsafe output I’m relying one disappears (e.g. because the transaction that produced it was RBF-ed) but in my case that’s ok, I’ll react to that and re-publish the tree of child transactions accordingly.
But let me know if you think that’s too much of a footgun for users, in that case I’ll architect my solution differently.