There is NOTHING special about Toyota’s coolant. There are only 2-3 coolant plants in the US…And all them make coolant that works well in Toyota’s. Toyota does NOT make coolant. They buy it from one of the 3 manufacturers and put their name on it.
As for buying pure coolant or a 50/50 mixture…the 50/50 mixture fairly recent. 10 years (maybe it was 20)…you could only buy 100% coolant. And I’ve NEVER bought the 50/50 mix. Seems like a waste to me…especially since it’s the same price.