Leave them a little long and sticking out the tip, then when you are done, before you put on the tip rib for final sanding, you can cut them off and make them flush and glue the wingtip rib on. Sometimes they do that.

I have about an hour in the building of it so far, maybe and hour and a half. The ribs are all on the spars, the shear webs are in, the wing tubes are in, and it is ready to be sheeted. Can't get the damn phone to quit ringing so I get to work on it about 5 minutes at a time. Slows you down a ton. It does build really fast though.