I have the 2020 model Unit, and it was a nice bike as it is, but I have made all kinds of experiments with the setup, many of them inspired by Andrew, like trying a 29x3" front tire. Didn't end up loving that, it made the bike slightly more cumbersome feeling without making the ride that much plusher. However, the greatest experiment has been mulletizing the bike! I almost didn't want to do that because I would have liked the convenience of one wheelsize per bike, but the results are so good that I'm willing to tolerate three different wheelsizes across my two mountainbikes (the enduro full suspension is 26", I feel no need to "upgrade" to larger wheels). I always felt like the bike would be more fun if it was just a little bit easier to bunnyhop and manual, and the 27,5" rear wheel resulted in just the right amount of playfulness. I was afraid that the bottom bracket would end up too low or I would feel the worse rollover factor of the smaller wheel, but in real life those things have not bothered me in the slightest.
Currently running 29"x2,6" front tire with 27,5"x2,8" rear (big rear tire was chosen to maximize the BB height) . Once the rear needs replacing, I will try 2,6" width on the rear too, as I don't feel the BB is too low at the moment.
The side benefit of the smaller rear wheel is also the slacker head angle without any special headsets. Compared to the approximately 63-64 degree head angle on my enduro bike, I quite like the feeling of the steeper angle on a bike like the Unit, I don't have any urge to try to make it DH-bike slack.
This ended up being quite a long monolog about my own opinions, but maybe it might be interesting to some people. At least I enjoy reading Andrew's opinions on his own bikes and experiments, even if I sometimes disagree with them.