My 2-cents.

First, a 50-1 mix is about 2% oil; a 25-1 mix about 4%. Yes, twice as
much oil but still very little of it. Unlike Steve, I've seen many
(not his hundreds) of 2-cycle engines seize up from too little oil,
but never from too much. Heck, I remember one guy that used 12.5-1 (2
qts. in 6 gallons) in his ultralight. Looked like he had a smoke
system! BTW, the ultralight engine manufacturers recommended 25-1 for
the first 25 hours for break in.

Not water cooled, but a real world example. About 20 years ago I built
and flew a gyrocopter. It used a WW II era 90HP, 4 cylinder engine.
The manufacgturer's recommended mix was 25 parts 130 Octane leaded
aviation gas to 1 part 40 wt. aviation (mineral) oil.

The 70's did away with the two aviation grades so the choice was 100
LL ( 100 Octane low lead ) or premium auto gas.

Most everyone also used 2-cycle oil and mixed it 50-1 because it's
mainly the oil used that determines the ratio. The 50-1 mix became the
standard shortly after the so-called "50-1 oil" came out and became
readily available, I think in the 50's.

A few folks with gryos and ultralights tried the very expensive "100-1
oil" and shortly faced engine rebuilds.

BTW, the gyro engine was high compression. I've been racking my brain
trying to remember, but am coming up blank. Anyway, that's why the 130
Octane gas.

Rick