Yes not much room! I kept truck for about 5 months than traded it on a 2026 Tundra. Now I'm stuck with custom seat covers front and back and a tool box for the bed. Plus floor matts.
I suppose it all depends on your requirements. I had two double cabs, a '15 and a '23. My kids were older by then. So special seats weren't needed. Everyone fit fine. I added a 12v port to the rear console for phone/game charging. All were happy. Also had a couple of buddies back there from time to time. They had no complaints. Are there dimensional differences with the 4th gen compared to previous gens?
I have a 2026 Pro and had a 2024 TRD OR, I wish Toyota made the Iso seats an option. I could fit in the rear seats (5'7'' 190lbs) in the regular tacoma but not behind the Iso seats