FYI, Spigen now sells a self-adhesive kickstand that you can adhere to pretty much any case:

https://www.amazon.com/gp/product/B01LW6NN8T/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

I've combined a case like this and an adhesive kickstand like this.

Couple things--
Probably the only viable placement of the adhesive kickstand is below the camera and above the power button, like this.

This way, the added kickstand doesn't add any ADDITIONAL thickness to the case, since you can place it on the "recessed" part of the case design.

CAVEATS: Due to our wide angle lens, you have to attach the kickstand sufficiently far below the camera area to make sure the wide angle lens doesn't pick it up on the edges of the photo. In turn, this forces you to place the kickstand basically hovering over the top portion of the power button hole, a little bit. It doesn't completely block the power button (you can still press it, but with your finger tip point, not the "pads" of your fingers) so if you use the fingerprint sensor, then this probably will not work for you.

Also, due to the design of the kickstand (and the placement) it only works horizontally, if that matters to you.

If you end up getting a different case, you can put a plate under it, so that your mount will work. I use one of this with my spigen case.

Universal Metal Plate 8 Pack for Magnetic Phone Car Mount Holder Cradle with Adhesive (Compatible with Magnetic Mounts) - 4 Rectangle and 4 Round, Black https://www.amazon.com/dp/B07CJ453V6/ref=cm_sw_r_cp_apa_i_zad7Db29KD5ZW

Also, these kickstand can be stuck to any case

Spigen U100 Universal Kickstand Compatible with Any Cellphone - Black (US Patent Pending) https://www.amazon.com/dp/B01LW6NN8T/ref=cm_sw_r_cp_apa_i_8dd7Db7K9ARNZ

Also,

I had the same Tough Armour on my S8 and haven't been able to replicate it. Also, I hated the Samsung kickstand case for all the reasons you mentioned.

I ended up getting the the Caseology Parallax Case and sticking this on it: https://www.amazon.com/dp/B01LW6NN8T/ref=cm_sw_r_cp_apa_i_Go8JFbM25VTRF?_encoding=UTF8&psc=1