I've got a 2019 ES350 UL and was wondering is it just the seats that are semi-aniline? Want to make sure I'm not wasting conditioner on surfaces that don't actually need conditioned.

In most cars, including the ES, leather, whether regular or semi-aniline, are on the “seating surfaces”. That’s actually a very common practice and car makers have been doing it for decades - you have to really move up the price chain to get it on more areas. I have the semi-aniline in my ’22 and you can feel the difference from the main seat area to the side trim or armrest cover.

From what I have read, the leather in newer cars has a a protective coating included with the dye color thereby sealing the leather which makes conditioners ineffective for at least 5 years especially if the vehicle is garaged and not out in the sun all the time. The care involved is a simply damp cloth or leather cleaning wipes on a regular basis and also ensure to vacuum the thread/seams to ensure dirt does not break down the stitching.

However, after 5 years or so, the coating make break down in which it makes it possible for a conditioner to penetrate the leather surface to some extent and may help to protect and ensure a longer life.

Keep in mind most leather seats are mostly vinyl on the bolsters, sides and rear of the seat. It is generally only the seating surface and back rest that have actual leather unless you move up to more expensive cars. If you look closely at the seat you can see a different between leather and vinyl especially in the grain.

Only on the seats. Everything else is nuluxe.

I asked the owner of the shop who does the ceramic coatings on my vehicles several years ago about interior coatings. He told me to use a damp cloth and just wipe the interior down. I’m a former Armor All addict so it took a while to convince me that he is right.

A bit OT, but...

I used to use Armor All, but I've read since then that the silicones in it can be actively destructive. I've since switched to a water-based shine for my tires. For interior surfaces and weatherstripping, I now use 303 Aerospace Protectant, touted as acting like sunscreen against UV rays. It smells a bit funky, but it's said to be effective enough to be a big favorite of recreational boaters.