What if I contribute 4% with company's 100 % matching.
Then I will pay my mortgage with extra money that is coming from my saving.

But again you can contribute 18K or 24 K annually if you are above 50. This means you can contribute like 14 to 16 percent.

What would you do in such case?
Contribute only 4 % and pay extra in mortgage
Or
Max out the contribution (i.e 16 % in my case) and pay just a regular mortgage payment..