NSEC3 Params

How often should the NSEC3 params (salt in particular) be changed.

I was sent an article on "rainbow"? attacks, and there was mention of changing/updating the NSEC3 salt might be beneficial. One problem I had with the piece was that I could not find a date for, so it might be obsolete, secondly I cold not find the author though the piece was reported to be from Digital Ocean.

JohnA

PS. Sorry to post this here I thought there was a DNSSEC mailing list, but everything gets rejected!