Yeah they recommended the same alkylate here.

I have to admit: I know very little of GM engines, and they sell very few cars here. It’s becoming even less relevant as EV’s are just dominating completely, passing 97% here last month.
For me personally it’s the snow blower and motorcycles, but both of those are new enough to handle E10. I still give them 98 as they sometimes have to sit idle due to weather, and we have winter from October to April.

I’ve heard the same about petrol being stored, but I’ve never had issues either. At least a year seems to be more than OK, but that is always 98.
95 E10 might be worse as it absorbs water over time…
Hope your rototiller works fine next time you use it !

In Norway, 98 is still ethanol free for older cars and engines only used seasonally like lawn mowers and snow plowers.

95 is of course (up to) 10% and that’s completely fine for anything even remotely modern and in use every now and then.

Like you said: hoses don’t like the ethanol, and it’s hydroscopic which is what can cause issues if left in for 6 months every year.