SergePhoto

The IQ (recipe) settings do not affect RAW files except for the Dynamic Range (DR) setting, which may force a higher ISO (DR200 requires base ISO x 2, DR400 requires base ISO x 4). Since a basic exposure parameter is affected, this does propagate to the RAW file. Please note that as mentioned above, Lightroom's Camera Profiles for the X-T5 do have film sims but (a) they're not necessary exactly the same as the built-in ones, and (b) they do not account for the other IQ settings such as tone and clarity. Those you will have to apply to the RAW file yourself in Lightroom. Capture One seems to have the closest approximations of the Fuji film sims, but again, you have to apply the other settings using the software sliders. If you're interested in keeping everything 100% Fuji, try the Fuji X RAW Studio software, which lets you play around with all of the IQ settings on your computer (but you do have to have your camera plugged in and USB set to BACKUP mode). This is the software a lot of people use to design new recipes.

I've used in-camera RAW conversion a few times, primarily to adjust exposure after the fact when I just wanted to transfer the JPEG straight from my camera to my phone and still have everything done SOOC. However, changing recipes, while certainly possible, is obviously a bit more cumbersome as you're updating many parameters at the same time. Keep in mind that one thing you can't always change is the DR setting, specifically you can't select a higher setting if the original shot was taken with an incompatible ISO value. This is also true of Fuji X RAW Studio. All things considered I love having the flexibility to alter the image in-camera after taking it, even if I don't use it very often. Just make sure you're set to F+RAW

Just curious, why do you not want to use the mechanical shutter? I can't see any possible advantage of using ES in this scenario.

The latest firmware for the X-T5 solves this.

Have not noticed this on my X-T5 but I'll test it. Are you able to change it back to RAW+F afterwards?

If you didn't shoot in RAW and only have JPEGs to look at, it's quite possible the grain setting was on. This might be reflected in the EXIF data of the JPEG. Not sure if C1 would show it but if you load it up in Fuji X RAW Studio, you should be able to see it under GRAIN EFFECT.