So I turn 50 next year, little confused on the mechanics of age 50+ catch up.

Google tells me that in 2020 the income limit on employer contributions is 285,000.

Employees are limited to 19,500

Age 50+ are allowed a 6,500 catch up contribution.

Total combined employee/employer limit is [for 50+] is 63,500.

So an employee could put in a max of 26,000 and Delta a max of 45,600 (16% of 285,000), but of course the total cannot exceed 63,500.

My confusion lies in the 6,500, does it matter who contributes it? Let's say I make 285,000 next year (sadly, the MEC's new war on greenslips combined with better weather next summer renders this scenario unlikely) such that Delta contributes the full 45,600. Does that mean to max it out I 'only' have to contribute 17,900 to meet the limit? In effect, Delta adds the 6,500 catchup?

I realize in many respects it doesn't actually matter, but its still annoying me that I can't figure it out. Let's say that [regardless of the financial wisdom of doing so] I want to make all of my 2020 401k contributions from my profit sharing check on Feb 14. If I think I will make >= 285,000 from Delta next year, how much should I contribute from PS?

I am clearly deep in the realm of very good problems to have. Appreciate any help