I have a pretty strong negative reaction to the idea of deliberately holding my child back so they're less bored when around kids who aren't as skilled. 

I'd much rather handle that problem in some other way.

Seems good! I wasn't really trying to do letters with my younger one until he had more words. Starting with letter sounds and playing with magnet letters or letter blocks is a good way to get them interested. 

I have now posted a couple decodable books on my website, here: https://tigrennatenn.neocities.org/decodable_books/ I expect to add more now that I've got a setup for making them digitally.

A great thing about Seuss is how well it scans. It's stunning to me how many children's books have truly awful meter. The whole point is to make it easy to read! They just don't even bother!

Oh wow, that is good to know. I tried experimenting with the font options and found that xx-large wasn't nearly big enough, I didn't realize I could just put "200px" in as the size and have that actually work. Awesome! I'll have to play with this more (assuming I don't get complaints about the cards not all being hand-drawn anymore, lol).

I definitely was not expecting a co-maintainer of Ankidroid to read this post, wow!! Thanks for uh, doing that!

He has not! I haven't examined that one for full decodability but it's probably pretty good. We might try it sometime.

1. Mostly fun. I think I likely would have done it anyway. Kids are people already, and can benefit from being able to read now even if it doesn't change future academic success.
2. Generally bribes are considered a useful practice in behaviorist psychology (mostly used on animals, but occasionally people). My vague understanding is that education literature shows that using extrinsic motivators like bribes can reduce intrinsic motivation for a task, sometimes. I am not worried about bribing them to do Anki; that's not that intrinsically motivating and I think it's worth the push to get him good enough at reading words to enjoy using the skill. I'm a tiny bit worried about bribing him to read, but I suspect that once he gets to escape velocity and is interested enough to read himself, he will do it anyway. I may move to reducing bribes for reading or limiting them to specific situations to limit any damage here.
3. You may overestimate the amount of effort I put into this. I enjoy it a lot, and the books are effort, but the Anki and such is really pretty straightforward and easy. I would say that, say, potty training was much more difficult (albeit shorter, thankfully). Certainly we spend a lot of time talking to him and trying to teach him about various subjects. He watches Numberblocks and we also spend a lot of time talking about numbers, reading books at bedtime, etc. I don't have as clear a curriculum for any of the other things you mention; if I did, maybe I'd use them. Reading unlocks independent learning for many other things, so I think it's a reasonable place to focus effort for that reason. But a lot of it is probably just "I could see a way to do this so I did" vs other subjects that are harder for me to teach. Hopefully that answers your question?

Very slightly! We've been interested in using household incentives/auctions for a long time (wrote web apps to use auctions to distribute chores twice before kids were born) and have wanted to incorporate that for a while, and we started using Numberblocks as a reading incentive before I'd ever heard of Alpha School. The post on ACX about Alpha School was the final push for me to start the token system, though.

I disagree-- I trust them, but I still think the process is important. If you don't want to read the words, you don't have to, but I feel better that they're there.

See, I think the description of the challenges you set for them is the most helpful part of this whole post! If you have any more you can think of, please do share them.

the basic idea was: hold the kid, with less and less support over time. Beyond that, I was just winging it.

Can you give more description of what you did in your 30-minute sessions? Holding the kid the whole time? Taking breaks? Did they/you get bored? Did you do any other playing in the water to make it more interesting for them?