I have a set of rear turn signal "bulbs" arriving Tuesday and will check them out, making a similar comparison video. They are the Amazenar 4-pack with 18 of type 3014 LEDs, with a circle of LEDs around the outside. The 3014 type are not as bright or intense as the 2835 type used on the fronts that I got, but the circular pattern should make them all right.
However, I just found a seller in Hong Kong of those brighter T10s with the 2835 type LEDs -- same as in that 10-pack from the seller in California, but this seller is selling just a pair. Per bulb it's more expensive, but as I really don't need 10, and it's only $4 with free shipping, I decided to get a pair of those as well. Obviously, shipping from Hong Kong versus neighboring California will take longer, so I'll have to do a comparison of the two after I get the second shipment. The 2835 type are brighter and more intense but arranged in a square pattern, so the distribution of light into the reflective surface of the signal pod may not be as good. We shall see!
There are even brighter LED options out there, like 5050 type, but those don't have integrated heat sinks so may not last as long because they'll cook themselves to death.