The film simulations dial over-rides everything else - if you want to use the custom settings (or use the menu to set film simulations) then you set the dial to “C” which essentially turns it off.
https://fujifilm-dsc.com/en/manual/x-t30-iii/about_this_camera/parts/#gsc.tab=0
I do not have a copy of this camera, but this page in the manual reads like you do have to change the dial to apply the custom settings, especially for the ACROS based simulation.
You are correct about other X series bodies (without the simulation dial) automatically applying the simulation chosen in the setup menus. Perhaps one of the Sim Dial users that show up here now and then will come across this posting and be able to help you.
p.s. Welcome to the forum.
Hello Fuji world, I'm new to photography and recently purchased the Fuji x100 vl so would love to get a brief tutorial on the initial setup of my camera i.e most beneficial beginner camera settings, how to best take pictures (angles, light/dark settings etc). Thanks