Enhanced Catch-up--discretionary or not?

I'm getting conflicting info on how discretionary the Enhanced Catch-ups for those age 60-83 is.

The Catch-up provision is already a discretionary provision in 401(k) and 403(b) plans.

And I understand the new enhanced catch-up rules (super catch-up?) are discretionary too.  But to what extent?

Can a plan have "regular" catch-ups but not the enhanced c/u?

Does the plan sponsor have discretion on both c/u's or just the regular one?

Under the Treasury’s proposed interpretation, a plan’s sponsor may design a plan to provide only an age 50 catch-up without the age 60-63 catch-up.

“The higher applicable dollar catch-up limit for participants attaining age 60 through 63 may, but is not required to be, included in an applicable employer plan. Thus, an applicable employer plan may also be designed to limit the catch-up contributions for those participants to the same applicable dollar catch-up limit that applies for all other catch-up eligible participants.”

Catch-up contributions [notice of proposed rulemaking], 90 Fed. Reg. 2645, 2649 fn. 6 (Jan. 13, 2025).

FTW's document has an opt-out for age 60-63 catch up.  Not sure about other providers.  ASC did not last I saw it, but that was about 6 months ago and could have changed.

And beyond RatherBeGolfing’s sensible point about what fits a plan’s documents, a plan’s sponsor and administrator might reread its service agreement with its recordkeeper to discern which services are obligated or omitted.

Thanks, all