Depending on the issue and excess length you might bend the cable out of the way, you might shorten it, or you might release and reattach it.
In this case the cable could be released and pulled down more, behind the clamping plate there is a little groove that the cable is not currently sitting in, see the extract below from the dealer's manual for R3000 derailleurs, showing the cable path.
If then it still hits something you could shorten it a touch (if you have the means to re-crimp the end). The blue coating is a friction reducing coating, it doesn't do anything at this end of the system so that doesn't matter.
