Hope I said this correctly but I was wondering if there could be a light that can connect to the Dynamic Lights top & bottom, sorta like in this image. Or have the top & bottom connect if they were near each other.

The red line is were the light would appear at. Could make some sort of neon-cube if you wanted.

Also... these lights reminds me of the lights from this mod here...
https://minecraft.curseforge.com/projects/modern-lights

Don't suppose there could be some light models of these in a way? I know you wanted to make it a lightweight mod but figure it wouldn't hurt to ask.

P.S.
I wonder if it's possible for these lights to not give off any light level but instead... 'glow' in the dark. Like the white texture shows as it were in a 15 block level but the blocks around it are in a 0 block light level. Some modded blocks like the Twilight Forest have bits of the textures on blocks glow in the dark but they give no light levels, unsure if that's possible to do that with these lights.

The first part is interesting, but probably not practical todo till 1.13+ as i dont have the blockstates todo it with right now without using a Tile Entity.

Second part, more models, im fine with making more light models, just haven't thought of any yet, and don't want to just rip off another mod, im up for suggestions for new models though.

Third part, this is possible, im looking into it now, it might come about sometime.

I can say that for the stuff I am building I definitely would want to keep those two blocks from connecting (going for a floating light feel with stacked horizontal edge lights to look like pillars). Maybe a second horizontal edge light set that has vertical connectivity. Or maybe an edge variant that places a light along each surface it detects when placed.

That said, I would absolutely LOVE a vertical variant of the edge lights with the exact same behavior. I have checked out the code just to see if i can get a variant of it working in 1.14.4.