With a triple being built for your own use, avoiding the extremes is probably a non issue. A bike shop assumes that a client might make a mistake.
If assembling a bike for someone else, then pilot error has to be considered.
Then there are duplications or near duplications.
Consider those and ultimate chain wrap capacity is probably more moderate than it is on paper.

I also don't like a chain that is so slack that any small bump in the road causes the chain to slap the chain stay.