Would it, it is just a rechargeable Plus with an auto-mode.
In theory if the game can tell it's not an "authentic" Go Plus it could break TOS but much like the overlay style IV Calcs I bet it can't and thus you won't have any trouble.
Not sure how I feel about them though, I've put so much time and money into my account that I'd hate to lose it on a technicality.
Speaking of time and money, I forgot to post about my Mewtwo Event experience.
Our town had Two EX Raid "tests", both at Sprint stores but on opposite sides of town.
I made two event pages on our local Facebook group so we could organize without people complaining they don't have a pass or cluttering the main group, etc.
I posted a ton of info on how to beat Mewtwo, group sizes, and made surveys to figure out how many of each team and at what time people would arrive.
I got there at 5:30 PM as the raids were from 6-7 PM and there were about 20 people there that early as well. By the time the raid started I'd say there was about 40 people there with a handful trickling in too.
Lots of people stopped and asked what we were doing, lots of people asking basic raid questions, and lots of people not wanting to wait or not wanting optimal group sizes (people were arguing with me about 8 being enough people until the first group did with 9 without telling anyone else, which is a grimy move in itself but whatever)m the usual.
Felt like a slightly more organized raid with your mix of people knowing what to do and not knowing what to do and everyone being all tense about it.
I spent most of the half hour I was there directing people into group, telling everyone team comps and IV spreads, and the like. One person said I sounded like a Disney staff person lol.
Anyways, the raid was simple enough as Mewtwo isn't super hard to handle. We got lucky and it had Hyper Beam so no big losses of Pokémon. One of the few Instinct only raids I've done so we got a whopping 10 balls and I caught it first throw, lol:
CP of 22XX so not bad, but hey it's a Mewtwo so that's already pretty dope.
It's now at a little over 3K CP and has made Raikou raids pretty easy.
Speaking of Raikou, did some more of those raids this weekend to get my friends theirs. I went from being 1-9 the first weekend of raids to being 5-8 this weekend lol. But one of my friends took all 8 attempts to get one and she got kicked out of two raids without being able to rejoin. So we opened a ticket and hopefully Niantic gets back to her. The Raikou she did catch was off a Critical so that was hype. I've got a 229X CP one now so I'm pretty much done Raikou hunting.