@teK-- how tall are you? I'm considering upgrading my small rune v3 to a medium titan 3.2 running mullet. I am only 165cm and have been riding small all my life with relatively long stem (40-50mm). Tempted to try upsizing to a medium with super stumpy stem like 30mm as i'm kinda in between sizes, but afraid it's gonna be too much top tube. I've tried medium frames (Liteville 601, Pole evolink), but none have worked thus far - top tube always feels too long and too much of a stretch.
Hey mate 172cm here, and my arms aren't particularly long for my height either.
Whether the Medium will fit you depends not only on the reach, but also the stack height, and how you're going to configure the bike.
I'm assuming you will set it up as a mullet? Also will you run a 170 or 160 fork?
The Banshee mullet charts assume a 160 fork, so if you go a 170 fork for example, that might help by shortening the reach by around 4mm. The stack height and head tube length on these are pretty generous. Unless you are riding steeps all the time, you may end up running minimal spacers and a 20mm (or less) rise bar. It's not the kind of frame to run lots of spacers just to bring the bars closer to you.
The titan has long chainstays, so if you run a 32mm stem then you will need to ride aggressively over the bars to get good grip out of the front tyre and stop it from lifting on climbs.
Compared to other modern enduro frames, I'd say the reach on the Titan is a bit shorter than average. Some people do go a size up on the Titan and just go super short stem with the saddle forward a bit more. (Dave Rulezman for example).
Another thing to consider is the seatpost insertion depth is not the best on this frame, so for your height it is likely you will only get 150mm drop and that is using a really low stack post like a Oneup V3.
Ultimately you can make this bike fit so long as you are clear what kind of bike you want... it is not going to be a super response whippy playful thing. Where it will shine is its high stiffness, and stability at high speeds.