i think you would be better off to use one big screen, unless you are starting from seed. having a male meshed in the screen would be hell to get rid of.
lst is an awesome artform; i personally think that you should NOT use screens unless you are growing from clone. if those are fem clones, then scrog away!! just use onee big screen, though, lol

love, brooke

ps, one of my untopped, lst only plants has 32 branchs at 42 days from seed after cuting 2 branches for clones! LST rocks!