Although the majority of ebikes I see are factory, I'm starting to see more DIY ebikes, and not just the more common hub motor, or bafang mid drive. While rolling up to the bike path, a bike crossed in front of me. I was thinking, is that an ebike, but didn't see a battery, but suspected there could be one in the rack bag. What caught my eye was what I first thought like a rear brake disc, but it looked too big, maybe 10 or 11 inches. As I got closer I could see it was aluminum, so not a disc. I made a right onto the path, riding behind the mystery bike, but as I got closer, and to the left, I spotted a small outrunner motor, mounted on the left chainstay. Upon closer inspection, I could see the belt, going down to the "disk", which was really big pulley. The motor was silent, and I'm sure it doesn't provide much power, but I think it still be fun to ride on the flat bike path; and this person looked like they were leisurely enjoying themselves too.
The fatter tire front hub tricycles also seem to be increasing in number. Not by a lot, but I see between 2 and 3 a day. None of them are DIY/kits so far.
Another general observation is that the people riding the faster class 3 ebikes seem to ride them pretty fast even when there's a lot of people using the bike/walking path. I'll open it up and ride fast when there's nobody around, but when it's busy, I'll ride a couple miles faster than everyone else when passing, and generally keep it pretty slow; slower than pedal bike speeds. These guys (actually both men and women) are going to hurt someone at some point, weaving in and out of foot traffic, like the people are pilons. I just don't want more laws, or enforcement, given I live in a state that I'm surprised doesn't fine you for greenhouse gas emissions if you fart.
The seasonal trend seems to be that the stand up scooter traffic is way way up; the sunny weather brought out triple the number of scooters and riding near the college campus will convince you that they're everywhere. And the one wheel/unicycles are growing in number too. I see 4 or 5 a day on average. I was talking to a guy when I was picking up some lunch, and he was telling me about his, and few others that are around. Apparently the super fast one that I've seen with the guy with a huge backpack, isn't just carrying around a battery. The guy I was talking to knows him and told me he's doing door-dash with it, LOL.