You may want to see this thread. It’s OK to add a EACA mid-year as long as it’s limited to new participants. But you can’t use the 6 month corrective distribution provision.
Even without submitting for a det letter on termination, I dont see the IRS going after a plan with a good faith amendment to include provisions of SECURE that had no actual impact on the plan or the benefits paid.
Of course I probably just jinxed everyone here...