I'm not privy to the security mechanisms of the integrated GPUs I've worked with however I've got a decent amount of experience with mostly tile based GPUs and I've never hit TLB misses as a reason the GPU is going slow. On the CPU? Sure, but unless they want to get a lot more specific on what these optimizations are it's a bit hard to piece together what's going on here.

GPUs don't like to read around in memory(neither do CPUs for that matter but then tend to branch and be a lot less predictable) so optimizing reads/writes are something you will do regardless. The painful parts of TBRs usually(but not universally) have to do with drawcalls setup and render target switching. I remember some of the early iPhones had pretty painfully low drawcalls limits associated with the overhead with dispatching the actual calls as opposed to triangle count or fillrate. It's fairly easy to put together the synthetic benchmarks to shake that out.