I don't see why not, I know that clones can be successfully taken during flower. Earlier the better. Would be a good way to get rid of the stragglers down under the canopy instead of just removing them, which is usually a good thing anyway.
I haven't tried it myself but I would trust air layering over taking a cutting to possibly save a strain any day!
I've even considered leaving potted or mini aero/hydroponic air layers attached to the plant throughout flowering to see if it supercharges the bud sites by having 2 root systems, etc.
Imagine having 1 big plant that has 5-10 different root systems besides the main one, all with different mediums, with different combinations of nutrients as well! Haha of course 1 of them would be a layer dipped into a gold fish bowl for some aquaponic action
( I know I know sounds crazy when you could just have that many plants. Mad science for the win!)