"The W2 from the company where the SE income was generated"

To clarify, then: You have a both an employer relationship (not SE) and a K-1 as Shareholder (partner) (SE).

"shows $4500.08 in Box 12"

Is that Coded S? That would be Payroll Deduction, then. Where is $6,750 coming from? Did you read the link I provided? Do you know if they adopted a standard "they have to earn $5,000" plan?

"and in Box 14 $1218 "Other""

There is no standard for Box 14; it's informational and there should be a short notation, such as Family Sick Leave.

"and $29522.27 "SCorpH". "

That would be taxable Health, medical coverage premium if a more than 2% shareholder. "A 2-percent shareholder-employee is eligible for an above-the-line deduction in arriving at Adjusted Gross Income (AGI) for amounts paid during the year for medical care premiums if the medical care coverage was established by the S corporation and the shareholder met the other self-employed medical insurance deduction requirements. If, however, the shareholder or the shareholder's spouse was eligible to participate in any subsidized health care plan, then the shareholder is not entitled to the above-the-line deduction. IRC § 162(l). (An above-the-line deduction is a deduction the IRS allows you to subtract from your annual gross income in order to arrive at your "adjusted gross income".)"

From: https://www.irs.gov/businesses/small-businesses-self-employed/s-corporation-compensation-and-medical...

"It does have an "X" in box 13 under retirement plan"

Because a SIMPLE Plan is an Employer plan. That might limit them for whatever else they might have wanted to do, such as Traditional IRA.