I tried to use both E6000 and Gorilla glue original:

I used a piece of blue tape as my palette and dipped seeds in the puddle, then placing them on the LED. The E6000 filmed over quickly and so I started breaking seeds trying to get to the uncured inner. I tried putting a small dab on the LED itself but it cured far too fast to place the seeds.

I used blue tape again and tried the Gorilla glue.

The gorilla glue dried slower but was more stringy, and definitely faster sticking. Brushing against prior placed seeds with the E6000 wasn't a big deal but the gorilla glue easily tangled seeds and instantly adhered. So this might just be a technique thing but both have their pros and cons. When I find some proper superglue I'll give that a chance. I'm not going to try hot glue since it dries so quick and this is a slow process.

To get to the below shown progress took around an hour, an hour and a half if you count fiddling with camera and lighting. Obviously, this is pretty slow.