The Crimson Binome
Hero
I don't use Lingering Injuries in my game, and this is the major reason why. If I say that any amount of magical healing will fix it, then nothing will ever linger more than a minute; the same is true if I say that it takes Lesser Restoration, if there's someone in the party who can cast that.d) and, how people read the stipulation about magical healing (whether any magical healing removes the injury, or whether it has to be a specific kind of (higher level) spell?
On the flip side, if I say that it takes a Greater Restoration or a Heal spell, then the injury might last for months (both in-game time and real-world time), and it could seriously impact the fun for the player. In some ways, it would be preferable to just have the character die outright, rather than to try and play with something like an Internal Injury, and I really don't want to put the players into the sort of position where they would want to think that way.
Honestly, I would prefer to deal Lasting Injuries in the form of HP damage, but it's just way too easy to recover HP in this edition. Even with the grittiest options in the book, there's nothing stopping a character from spending all of their hit dice to go from zero to full after a single short rest. (The only impact from the grit dials is that they won't be able to do that multiple times in succession, and it might take as long as eight hours to trigger that short rest.) With something like AD&D healing times, a single injury for 5 damage would still be meaningful, because it would take five nights to heal; if I could deal just a few damage every day, they would eventually be worn down by the end of the adventure. With default healing times in 5E, I have to run through all of their HP every day before they can start to feel threatened :-/