I haven't specified a jump measurement. I'm open to and encourage suggestions from anyone knowledgeable. The barrel and dummy round are in the mail. Is jump a consideration for a person who doesn't clean barrels anymore? Does chasing lands extend usable barrel life?
In my experience, you only chase the lands when it stops shooting. If you do it before that, you are chasing your tail. When a barrel stops shooting I look for things that are loose, check scope, clean to bare metal (need borescope for this one), seat bullet closer to the lands. SOMETIMES this will make a barrel shoot acceptably again. For max performance/accuracy, when a barrel quits shooting and cleaning won't fix it, I am done with it for anything serious. I am not taking a barrel with a reworked load on an important hunt or shooting it at a national or regional level match. I use them for practice, local matches, culling does.
Compared to the cost of a 2 day match or a back country hunt, a barrel is damn cheap. That said, I would throat it to around a .020" jump when designing the reamer. Bore/groove dimensions and reamer dimension variance as well as bullet diameter variance will have some effect. If chambering to a dummy cartridge with a throater you can get it nuts on.
I have not shot any 106 yet. With 115 dtac and Hornady 105 bthp and 108 berger target I would have the smith run the throated to get a .040" jump.
I honestly don't custom throat my chambers. Many of them, especially the 243AI have a lot of bullet in the case. Unless you are worried about case capacity, I have had no issues with accuracy or donuts, even with brass fired 30x+ the way I size. I get 3200fps+ with 105s in 26" 243AI barrels. This is with h1000 and n165, so more speed is probably there for the taking with a different powder, even with the short throat.
If it is a fun gun and not a serious one, I would throat it to touch with the bt junction in the correct spot. You can seat deeper for jump and seat longer for wear for max rounds of playing around. For something serious, I would throat to my liking, and, when accuracy dropped, I would scrap it for a new one.