Tan Eternabond...well duhh..I never checked they had it.
I have bought some from this Ebay seller as he sold it by the foot and I needed a short piece of 2" white.
They sell five colors of Dicor but there is a question as to using it on some TPO roofs. Won't actually damage it but can..on some..cause bubbles which no one wants.
The self leveling works fine for me but I found it levels better when it is cool like 55-60 where as when it was hot it setup quicker. It will stick...and stick well. I have never had it come off.
If you used Tan Eternabond then you could not use any sealant or just run a narrow bead along the seam
Dicor Tan Self Leveling Lap Sealant - Roof Care & Sealants - RV Maintenance