As far as I'm aware you can still earn random inspirations from defeating enemies and you can even combine three of the same inspiration into a different one you might need more.
Well, as someone that has solo'd a PB to 50 way back on live before the QoL changes we have currently, this comment holds no water. If you are so uptight about spending a piddling amount of influence on inspirations that will solve the issue that you're having, I don't know what to tell you. Read the pages of people giving the same suggestions I have throughout this thread and hope one infiltrates your brain.