Zardnaar
Legend
Thanks for the kind words. I'm somewhat familiar with Isle of Dread, but not with the others you mention so I can't give any specific advice on those. Exploration challenges can range from abstract overland travel to granular room or even object interaction depending on the level of "zoom." The key thing in my view is the DM needs to be good on description, trade-offs and meaningful decisions need to be present at all levels of zoom, and mechanical process should not get in the way. Traditional hexcrawls tend to fail on all three points in my experience and also suffer from the 15-minute work day or 5-minute work day, whatever we call that now. (The latter is caused by a lack of time pressure.)
I'm currently tinkering with a hexcrawl right now so this stuff is on my mind. If you have some more specific ideas for discussion, it might be good for another thread. This is just my broad strokes advice. I don't want to derail mellored's thread.
Similar stuff, I have not figured it out in the 5E context.
Pathfinder Kingmaker they used keyed encounters on various hexes and mixed in things like land marks and resources for you to find. You also got xp for exploring the hexes. There were also little side quests added with various NPCs willing to reward you in various ways for things you discovered. They might want monster parts, eggs, or artefacts from various ruins. With limited daily healing though and no expectation of the 6-8 encounters thing though you could get worn down or even killed out right by say Wyvern poison and since save or dies are out the window its hard threatening the PCs since everything is just damage for the most part.
On the Isle of Dread you might want to think hard before engaging a Wyvern and it is fine for a single encounter for the day (avoid, run, kill and maybe get killed). Its the main reason I am struggling with exploration themed encounters as you have to grind down the party resources which is harder. Works OK at level 1-3 to some extent in 5E after that not so much.