I don't see an issue with taking multiple short rests in a row, if they stay at 1 hour long.
I plan on running through ToD playing very close to the core rules as possible, but I already know that I will eventually use 15 minute short rests, if I do I will have to change a few abilities like this to only work say when under half hit points.
If anything, taking multiple short rests in a row is less optimal, because you don't get to actually use all your refreshed abilities in between. Aside from healing up or getting back a few spell slots.
All the healing up portion of Second Wind does is throw the middle finger to the cleric's role in D&D.
I hope Cybit's right and you can't take multiple short rests in a row as per RAW. It would further force any cleric characters to act like healbots, since out of combat healing spells are wasted on the fighter, if he can just regenerate the same amount shortly. If gives way too strong an incentive for the fighter to say, let's rest for another two hours, even if the rest of the group has run out of hit dice and is just sitting there.
Same problem as people complained about the 5 minute workday. Instead it would be something like a 30 second work afternoon. It's a waste of cure spells to cast them out of combat, meaning the best and only time they should be cast is during combat, on the fighter. Fighter is definitely the tank role, sponge up all the damage while the cleric heals you, so is now an in-combat healbot thanks to Second Wind not relying on hit dice and having no limits except finding a safe space to rest or some story timer which will put the players at odds with the DM.
I don't understand why they just didn't let the fighter spend a hit dice on a reaction to taking damage. Total, unadulterated facepalm.
If a 20th level fighter has effectively ~140 HP base, Second Wind probably doubles it, if not more, since Second Wind will be 30 HP per shot. If you can rest ten times in a day, and that's tripling your HP. But then you still have 20(d10 +con) HP left in your hit dice.