Re: Going after the Sea Trout.
Down here on the "south coast", Guld Coast we call them "specks".
I like your patterns however I tend to really lean toward flashy & noisy. My experience has the larger the fly the larger the fish.
Grew up chasing these beauties and use casting tackle 1/2 the time. For this we chunk (we don't 'cast' in Texas, we 'chunk') large topwater like a Rapala Skitter-Walk, spoons like Johnson Silver Minnow often with tails attached, and 4"-6" paddle tail lead headed jigs.
So this causes me to reach for bigger flies, like big bushy slow sinking streamers, often offshore looking streamers. A top speck lure for casting is called "Corkie" which is big slow sink soft plastic plug that can be worked very slow. Released a 6#+ trout on a cold cold Feb day out of Palacios, TX, darn finger were freezing on a 6" long very bushy Lefty's. Was working the streamer very slow just above the oysters in 3' of water.
Thus I most often use a 8-9 wt and throw large flashy streamers, big noisy poppers. With poppers lean big and make a lot of noise like a dying mullet as specks often like a big mouth full. Not a fan of heavy Cousers, IMHO they are what I call a "chuck & duck", more jig than fly. If I want a fly to sink then I use Sink Tip line.
For us the best fishing "speck" fishing is coming, Nov, Dec, Jan, Feb.
Under the lights specks tend to run smaller however the action can be fast & furious. Casting is much shorter distance and you can pull out the 5-6 wt stuff. Again flashy is the key. Went to college in far south Texas (Tex A&I, go Hoggies!!) and we fished the famed Baffin Bay out of Rivera under lights. Some nights it was what we call "stupid" easy.
They are the finest looking fish right out of the water, that yellow mouth and big top teeth. Under the lights they are iridescent.
Top table fair, we love 'em fried down here.