I'm currently buying gear for a rtw trip. I am tall-ish, but I have a ridiculously short torso to begin with, and it's even shorter after a severe back injury (several compression fractures, now T2-T7 are fused) leaving me almost an inch shorter. My torso length is just under 15".
I want a backpack with great support due to my back injury. I am an exceptionally light packer, and wouldn't anticipate any problem with about 30L. I purchased the Osprey Farpoint 40 (S/M) and it was just too tall. Any suggestions would be greatly appreciated!
Find a store with knowledgeable staff. One where they have the Osprey pack size tool.
This is the best tool I've seen for getting an accurate torso measurement.
The Farpoint 40 s/m is intended to fit a 15" torso length. When you say you 'purchased the Farpoint and it was too tall', I have to ask where did you purchase it and how is it 'too tall'. If you ordered online and just put it on your back and decided for yourself it was 'too tall', that's not good enough. Did you buy in a store, were you fitted by someone, did you walk around with weight in the pack?
You need someone to measure you and to fit a pack to you. You need someone who knows what they are doing and that eliminates 90%+ of 'salespeople' in the stores. You have to find someone who knows how to fit a pack properly.
I would go to a good outdoor store like REI and tell them you have a back issue and want to know who is the most knowledgeable person in their store when it comes to fitting packs. A pack is a technical product and as such it's 'technical'. To get it right you or the person fitting a pack for you needs to understand all the technical issues involved and why they matter. Watch this video to see some of the points that have to be covered. https://www.youtube.com/watch?v=Zy4gs3PHlws
It may be that to get a good fit given your back injury, you will need to go to a completely customized pack. That will probably not be found in a pack around 32L at all. You may need to go to a larger pack even though you don't use all the capacity it gives you. It may be that you cannot find what you want in a travel pack which the Farpoint is. I note you called it a 'backpack', it is not a backpack. You may need to go to a backpack however which will not have the advantage of the 'stow away' harness that the Farpoint travel pack does. You might find for example that the Osprey KODE 32 fits you well as it is also intended to fit a 15" torso (again assuming you actually have that torso length). It is a ski/snowshoe pack but that doesn't matter if it will work for YOU. What make or model of pack isn't as important as fit. I would not try to suggest any pack to you. You have to try then to find the one for you.
It all starts with finding that knowledgeable person to help you. If they don't measure you; fit the pack to you and show you how to adjust the hip belt, shoulder straps, load lifters and sternum strap; if they don't load the pack with weight and ask you to walk around the store to see how it feels, GO TO ANOTHER STORE.