Having recently played around with risers on my 2016 DL1000, I can confirm that the front brake line is the limiting factor. No re-routing of the line can help as the short distance between the master cylinder and the manifold block on the front frame is the problem. No cutting of cable ties, nor re-routing of the line under the top triple clamp, will help (that actually hurts the situation due to the angled nipple on the manifold block).
I tried a 30 mm straight, non angled riser, and after removing all cable restraints from the triple clamp, both throttle/brake and clutch side, it kind-of worked. Turning the forks full lock on the clutch side was OK, but full lock on the brake side was definitely stressing the front brake line. Too much for me to be ever comfortable leaving it like that, even though the forks are really never turned into the lock towards the brake side.
I read information that 25 mm risers will work on 2014+ without issue other than maybe removing the retainer for the clutch line under the triple clamp. I'm not saying I doubt that, but after the 30 mm experience and knowing what that looked like, I KNEW I would be fine with 20 mm risers.
So, I bought 20mm SW-Motech straight risers. They fit perfectly, although I did still remove the clutch line retaining hardware from under the triple clamp. The brake side was left completely alone. There's no discomforting level of stress on any cable / hose line with the 20 mm's. Would 25 mm be alright? Maybe, but 20 mm, I can speak to with absolute certainty.
For me, the small bump in height really does improve my upright riding posture, but I wasn't needing anything gigantic as far as rise anyway (I'm 6'4" on a stock seat).