Yes, use what works for your engine, and you are comfortable with. If it isn't premixed 50/40, always use distilled water and use distilled water to flush unless your water source is naturally soft, low TDS water. Softened water is not recommended due to the higher ionic strength, specifically chloride that can cause corrosion to be accelerated.
Thanks for the tip on the Prestone. I missed that one six months ago when I was in the midst of coolant purgatory. One manufacturer discontinued the original coolant and was recommending a new coolant that would clog if any trace of the original coolant remained, and the engine cooling system was designed not to fully drain.

At the same time, I had a twenty year old engine designed for the toxic green coolant, and I was trying to find a reasonable replacement, with a bankrupt manufacturer. I wish I had known about it then; I sure could have used the Prestone. Sigh. Win some, lose some...
All the best,
Peter