I know I’ve read playing a song at a faster speed can help with mastery but what if I practiced a setlist at a faster speed every time? Would it mess up my timing or could I practice at 1.25x or more and shave time off of my sessions (or practice more songs)?
And yes I know this probably isn’t the way 
When I want to learn a riff I generally do this, but I am not sure I see the value in longer play at higher speed.
That’s an interesting thought! Maybe not the whole setlist, but using it as-needed on specific songs could work.
On the flip side, it could make playing them at tempo feel boring afterward?
I thought about that boring side. 
I went through about 10 of our songs at 1.25 speed and I learned a whole lot.
I’m going to call this “punk rock practice” and I’m not doing it frequently.
By my rough math I saved 10+ minutes of practice time tonight so I worked in some fun songs that aren’t on my set list.
Another thing I did earlier today was pop open YouTube and play random bass tabs that popped up. I’m super stoked that a good deal of the songs I bumped into I could play reasonably on a try or 2.
I really need to do some more covers for here soon.
I do this on most of my songs on the set list. It’s very beneficial to learn slower than normal speed so your can work on your form, then gradually speed up to 100%. The fun begins when I start speeding it up to 120%. When I drop back down to original speed I’m more relax and chill as it’s not the max speed that I play.
When you over prepared the final result usually better than your original version.
Yes it’s helpful to develop your speed and you should be capable of playing every song faster than the standard tempo. I don’t know if I’d go so far as to practice them all faster, maybe if there are some difficult songs that are challenging for you. Practicing faster shouldn’t mess up your timing any more than practicing slower. Slower is often harder, it will often show where your weaknesses are… If you can’t play slower, then you need to work on that more 
Ps. I started writing this about 3hrs before I posted it 
Agree with @howard on this, using it to practice a part of a song is useful. When I’ve tried this with a full song, especially songs that already have pace, it screws up my timing when I try to slow back down. I can’t help but want to play it at 110% or whatever I was practicing it.
Back in high school when I was headed down the road toward being a Piano Performance major in college, I had a teacher that told me once I knew a song I should start every practice session playing it once as fast as I possibly can, then go back to proper speed. And to make sure that I played it more at regular speed way more than too fast.
So yeah, while there is definite value in being able to play a song at faster than normal speed, you don’t want to do it continually or that will become your “normal” speed and you’ll run into problems when you join up with the rest of your band.
Those are pretty good reasons, and yes to you posting more covers!
Whilst learning Muse Hysteria I accidentally selected 1.25 instead of .75. I nearly did myself a serious injury. 
hahaha that’s funny. I messed around with it earlier in my playing and I played it so slow it sounded like it had a swing to it