On Thu, Jun 07, 2018 at 11:31:15AM -0400, harbor235 <harbor235@gmail.com> wrote a message of 5 lines which said:

I was hoping for some DNS wisdom,

Then this is more a dns-operations mailing list issue.

would a change in a SOA record cause a DNSSEC broken trust chain? incorrect RRSIG?

No. The SOA record is not part of the trust chain (unless of course it is the record you query).