It's been a while- I had some successes and plenty of failures. I tried chaining Snorunts at the lake near Snowpoint- even though the area is massive, the snowy background is too bright and makes it hard to see. Also, the 20% appearance rate is not that great and they only come out at night. So I gave up after a few failures.
I tried chaining Bagons yet again. The map is terrible because it's too narrow vertically and there is an obstructed row, which is not safe to run into. As a pokeradar exclusive, Bagons are hard to chain, so I was hoping for a lucky early appearance. Eventually, I gave up and moved onto something else.
I chained Pichus with Static to build up my confidence. I'm not fond of the Trophy Garden map, but it's not the worst map I've chained on. I also took a half-hearted stab at chaining Happiny, but the appearance rate is low and I already had Eevees active on the map. The experience rate is great though, so I might try again later.
I tried Bagons once more and finally succeeded after many failed attempts. I'm not sure why it worked this time, but I paid closer attention to the tiles and always reset if I couldn't get a good look at all 4 tiles. I stopped short of 40 because of the risks- I was aiming for 36, then gave in and chained up to 38 and got my first Bagon shortly after. The gap between shinies was much longer than average- probably due to that obstructed row. But I didn't break my chain until a shiny 4-patch on an edge with 30 repels left, so I'm very happy with how I did. I hope to never go back there ever again.
I may put up pictures later, but they're nothing impressive.