A 2015 Tacoma joined my fleet a year and a half ago, alongside my 2003 Tacoma. It's been in California most of the time while I live in Missouri, so it's not getting driven much or built up with the desired features particularly fast...
The Alu-Cab canopy is one of the options being considered, as is an
UnderCover Ridgelander aluminum tonneau. That pesky Gen 2 higher-sides-than-the-ends bed is a problem with several of the options on my list. The Ridgelander, in fact, isn't supported for the Gen 2 Tacoma.
But there may be an option that's not a wider gap-filling bulb seal. Perhaps others have tried this, in which case feedback would be helpful.
KB Voodoo makes a range of fabricated sheet metal products for Tacomas, including a tailgate edge and bed side rail caps to replace the plastic originals. As they're sheet metal rather than molded plastic, they're a lot "flatter". The lower profile of the
KB Voodoo bed side rails might allow either an Alu-Cab canopy and/or Ridgelander tonneau to fit better, especially sealing around the tailgate.