muted flavors are usually caused by
-too low power
-not right amount of cotton
-juice not steeped/mixed properly
-bad coil
If you are using the .5 stock coil, the power range seems decent. I usually settle around 30w when I use a .5 single coil. But check your battery charge level and charge it if its too low
Since you are using a pre-made coil, we shall visit #2 along with #4
I am not familiar with Lost Art, but I have tried Cuttwood. Its a 60vg juice, so I cant imagine its too thick to wick on those coils. But if you need to, you can toss a few drops of distilled water into the mix and shake it up to thin it out a bit. Makes wicking a little easier to keep up with demand.
But in all fairness, I have tried a few bottles of Cuttwood (melons, unicorn, sugar drizzle). And all of them needed a good long sit before they started to taste good to me. So maybe its just a steeping issue with yours.
Bad coil. it happens with these pre-mades. If you buy a pack of 5, you might be lucky and get all 5 that work. Occasionally, one or more will be bad. Bad wire, bad cotton, bad o-ring. It happens. Do you have another coil you can try? Also looks like a single horizontal coil in there, similar to how my old Kanger subtank coils were. I would take a very small sewing needle, and push it through the center a few times to break up the cotton inside the coil. And I would then make sure the cotton on the ends by the holes felt fluffy and moved a bit. It helped me with wicking.
Those are my basic suggestions. As far as other tanks go, as long as its 510 threaded (most are), it will work. I would suggest looking at a Kanger Subtank Mini. It seems to be a standard of great price, ease of use, and great flavor. The coils are available 95% of places, but it also comes with a rebuildable deck if you ddecide to give building your own coils a shot.