I’m just shy of 6ft 3 and used to ride a large FF29er. I used mine for fairly racey stuff (like er, racing) and had a pretty long, negative rise stem on it). Also used to run a layback thompson post but this was to get the ass up, head down position that I liked for racing. For trail riding I’d have maybe gone for a slightly shorter stem, but I’d still go negative rise just to get the front lower.
What bars are you running? I ran mine with some flat 700mm’s again to pitch me forward and lower – I did have a set of risers on it but it made it way too high at the front. Running a lower front end I also found it gripped better and just handled a lot better than when I had it shorter and more upright.
Pic below is of it prior to it being sold set up for my mate who is a little shorter than me (hence the inline post).