More generally, I think that awesome exploration needs to rest on awesome journey mechanics.
I agree. I think the best way is to just take the game you like the most for its base mechanics (Shadowdark in my case) and then slap the jorney and domain mechanics you like onto them. Also you need to design a more open and sandbox campaign in general to support exploration. Personally I use different journey mechanics for different purpose:
a) Target location unknown / general detailled exploration of an area: pathcrawl
b) Target known / Journey from a to b for the first time or through dangerous area: A challenge similar to the LOTR TTRPG
c) trivial journey / safe road / route that heroes already travel a lot and know in and out: Just a short montage narration, no dice roll.
Basically I zoom in and slow time the more focus is on the actual exploration and jorney. Or zoom out and flash forward if the adventure is not about the journey. The techniques can also be combined. For example for a quest like "Somewhere in the kings wood there is an old wizard tower. Find and and bring back to the city the old tome of the wizard".
1. The wood is well known so just a short skill challenge for the journey to the edge of the wood. The outcome result makes the heroes come in downfall or in tailwind (metaphorically speaking) so they get a slight malus or bonus, punishment or reward etc.
2. Pathcrawl in the forest to find the wizards tower.
3. Handwaving and little montage to return to the city.