You can drill LR no problem, just keep it damp.
The only thing that may die off is sponge, if there is a lot you could scrub and dunk it, but really that's not a big issue.
I set rock in brutes, pull some pieces, set on a ply template, see what fits, drill, play around w/it, it's probably out of water an hour or so, and I might drip SW on it if it's getting dry, but really reefs are often exposed to air half a day maybe on low tides, it's not an issue.
There's a fine line between owning your tank, and having your tank own you!_________________________________________
120G SCA starfire, tunze 1073.02 return pump, Geisemann reflexx 4xT5, 2x panorama pro LED strips, 2x Vortech MP 20's, 40g sump w/ fuge.