TMs, especially if globally famous, can very often be legally protected in other languages too.
I'm not an attorney, but would personally suggest deleting the IDNs unless they are earning substantal amounts of money; seems counter-intuitive, but TMs earning at least many thousands per month can sometimes be worth the risk, if one plays it right.
But again, to be clear, if the domains are earning little to nothing with little expectation of revenues increasing much, then deleting them, in my view, is the way to go.
Ron