If I ever run a 5e game again I'll definitely use this. But I think modern D&D stuff, at least up until I quit playing 5e, is largely built around the idea you can plow though most encounters without worrying much about resource management since its so easy to recover. So adventures would need to be set up with the idea that the players will have to use resources sparingly and be able to avoid and get around combat encounters in order to save scarce spells, HP, etc. This approach would probably require a reworking of adventure path stuff, at least the ones I looked at.
If I used published mods I'd have to do some rewriting. Add more encounters, figure out how to handle the fact that the "next" encounter is 20 feet away but they never hear a fight and so on.
A lot of mods are more work and less flexible than I want to bother with so I do my own stuff. Using GR or not doesn't really change that.








