Welcome! The biggest question is, what do you need to change? A mod I’d consider if I had a 4.4 would be to retrofit a sliding rear seat track from the 4.3, as that feature was removed in 2013. But that might not be a priority for you

We’re happy to help out but you might want to be a bit more specific. One thing that’s affordable and almost universally agreed upon is to reduce the noise infiltration in the rear. Many owners have stuffed insulation in the rear plastic panels around the back seat and the trunk, to cut down on road noise. It’s pretty quick, and cheap.
2012 RAV4 Base FWD. Upgraded to large front brakes and 3rd row rear springs.
Link to SAE J2807 test description

That Dam Towing Test: New SAE Trailering Standards Explained
The new standards ask: Can you climb the Davis Dam grade?