It's a resource that supports it in 5e. I understand you know how to run it. I am saying it's a helpful resource which focuses on it for 5e. If you have not read it, I think you'd find it useful.
I will provide some examples. Tomb of Annihilation has backgrounds specifically for a hexcrawl setting. It has more advanced hexcrawl weather rules. It has a city setting which is focused as a starting point and returning point to support a hexcrawl around that city. It has a series of sidequest rules for hexcrawls. It has travel distance issue rules, navigation issue rules, dehydration rules, disease rules, rules for varying wandering monsters depending on broader areas of hexcrawls on a map, etc. all of which is focused on 5e and hexcrawls.