Alex, I'm probably not a lot of help here. But I just sold my Skeeter that had a 90 hp Mercury on it. I just ran the Walmart/Bass Pro Mercury Quicksilver in it. It seemed to do just fine on it and I ran it for about six years up until I sold it.
But now I've got a Mercury 225 Optimax and they have been telling me we need to run the high dollar stuff in it. WOW, it is about $35.00 a gallon, but I guess a small expense in the big picture with that motor costing as much as it does and what it would cost to replace it.
I certainly don't have any knowledge of what is right or wrong, just telling what I have done.
Life should NOT be a journey to the grave arriving safely in an attractive and well preserved body, rather to skid in sideways, body used up and totally worn out screaming 'WOO~HOO what a ride!'