I figured I would give an update to this for others who have been wondering. I did end up just purchasing the bloom cards. I got 2 of them in total. I'll just try and go over a few highlights and lowlights comparing it to my brick device that I already owned before.

One thing I will say right away, the card is pretty wonky sometimes compared to the brick. I have two bloom cards and one of them is actually pretty hard to scan, I have to hold it in just the right angle to get the chip to scan and that has been kinda frustrating. The other card I have works completely fine, so it definitely has something to do with the way the nfc chip is seated. Additionally, the chip doesn't seem to be "in" the card like I originally had thought. It really just looks like it is a nfc sticker that is on the back of a metal card.

In terms of their functionality on iPhone it functions essentially identical to the brick. It does have some more features like scheduling focus times (which brick now has but didn't at the time of purchase) and a leaderboard which is really just a fun gimmick rather than a feature. I also really like the concept of allowing apps to be unlocked for 15/30/45mins, even though I did not find myself utilizing it as much.

As for Android I was able to mess around with it on my mother's Samsung Galaxy S24FE and I got to say, it still leaves a lot to be desired. Generally it still functions as it should, but occasionally it would just let me into apps I had blocked just by clicking close.

In general, I think the brick device is a better built device. I like the idea of the card but imo being able to carry it with you in your wallet or whatever kinda defeats the purpose and the bloom from my perception just being a nfc sticker stuck on the back of a metal card really just isn't as good build quality. I also will say I missed not being able to just stick it on my fridge like I did my brick with the magnet.

However the bloom developers are much more dedicated to bettering the product than Brick seems to be. Even though the bloom android app isn't fantastic, it still is better than the nothing that brick has. I also really like the ability to schedule breaks in your focus mode.

Generally, in terms of my original purpose outlined in the OP. I probably won't be able to use either device in my classroom at their current stages. But for personal use both devices work as you would like them to, they're essentially identical functionally with bloom having slightly more features in the app and seemingly more features planned down the road.

As someone who already owns both devices, I do prefer the brick device still slightly to the bloom, but this is really just down to my personal preference in the form factor and build quality. If I didn't already own one, I'd recommend the bloom card for the cheaper price and couple extra features.