HT can normally only be used up to 27c . Work that one out? If you ring fball they will advice you to use pressure sensitive over under floor heating. They will say DONT use HT adhesive. As above, work that one out ! As for Karndeans HT glue, i cant find any up to date specs for it on their website so dont know.
as i've said in previous posts HT adhesives are pointless PS addys do 90% of jobs and do them better than HT