It should be possible, but there are always some tradeoffs to be made. A long display will take a longer time to shift out the data between each latch into the display. When latching data for a very small color bit (which is displayed for a very short amount of time), the display will be blank while waiting for data to latch. At high color depth (lots of small color bits), there’s more time being spent waiting for data with a blank display, so the overall brightness is dimmer. This may not be a problem for your application.
Good thing to do is just try this, you don’t need all the panels to test. Define a sketch for the panel setup you want to use, and try it with one panel, and draw the content you want to display (making sure at least some is visible on the first panel in the chain), and see how it looks.
I can’t remember off the top of my head if the Teensy 3.6 can reasonable handle 8k pixels with 36-bit color depth at a reasonable refresh rate (you can test for yourself)
What size displays are you using? I’m concerned when you say 512x16, as the only 32x16 panels I know of are P6 (like what Adafruit sells and they’re /16 scan and supported), or P10 which are usually /4 or /8, and not supported. I’d like to add /4 and /8 support, but it’s not nearly as straightforward to do as I anticipated when I got into the project.