Restore old aspiration window to 16

Tested directly at LTC because previous long
test series on this topic shows it is TC dependant.

Tested with no-regression mode because gets rid of
an ugly and ad-hoc rule.

Test at LTC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 67918 W: 10590 L: 10541 D: 46787

bench: 7926803