LST is low stress.. don't snap the stem or that becomes high stress, lol...
bend all you want. i'd get it near horizontal - tied down top and a stake in middle or something so it doesn't arch.
the key is when to let the "top" grow vertically to catch up -- and it will dominate growth once you let it grow north. it may need ~2 weeks to catch up. with an autoflower, that's obviosuly a guesstimate at best as to when that is.
you can top if you want. you should have ~30" to play with assuming ~24" for light and 6" for spacing above it.
With an auto, i'd LST over topping. Bend it down 45-degree to each 90-degree alternating nodes. they'll all growth vertically on an easy path.. make sure none try to snake around a limb or apical meristem. force them on direct route. won't have time for much auxiliary growth beyond what is on the meristem.