I don't think you can generalize too much from a single ride. Some days you're just "off." But as I wrote, enough people have initial difficulties on keto that it's called the "keto flu." I never had any problems, however.

The "boost" is a single protein bar, with around 10 grams net carbs. I only started doing this when I noticed that 2 to 2 1/2 hrs into a ride, I would start feeling pretty weak. One time I measured my blood glucose at that point, and it was 68. So now if I'm going to ride 2.5 hours or more, I eat the nut bar 2 hours into the ride.

I found from my personal experience that consuming one bottle of water with a single Endurolyte tablet helped keep cramping down to a minimum on my diet. I'm just saying that works for me. I can't vouch for any supplements, since they're totally unregulated in the US, and all sorts of crap is being marketed as "health food."

By the way, as I mentioned, I do keto, or what a purist might term "loose keto" for one reason -- to keep my blood glucose under 125 at all times. And I can prove that it works for me, since I test my blood regularly. I don't claim it's any magical way of eating or something that everyone should do. But if you're a t2 diabetic / pre-diabetic, it's something that's certainly worth trying in order to stay of metformin or similar drugs.