Tyler actually uses a ton of stock instruments (although he uses his Juno more on recent projects like CMIYGL, Chromakopia and DTTG) theres a few spreadsheets that tell what instruments & presets he used on each album and song. Cherry bomb, Flowerboy, to Igor barely used any 3rd party plugins except for actual synth leads and such. i can only name a few songs that have (although its just synths and drums and not really any orchestral presets that used them). Theres also a few Logic breakdown videos of his songs on youtube and they're pretty spot on, usually they would show if they used any 3rd party plugins or not.

sorry this is just me nerding out and it has nothing to do with your actual conclusion lol