Power lever angle below 12 degrees, Flight / Taxi to "Flight", on the -100 all 3 weight-on-wheels sensors showing on the ground (-400 only needs the main gear WOW) will deploy the roll spoilers in ground mode (and ground spoilers on the -100). The -200s we used to have did not do this; don't know if this applies to all -200s or if there is a mod. We were weight-restricted at certain very short fields in the -200 as a result. Never touched a -300 so couldn't say there.