You won't have time for a coffee, even if you have the money to buy one, you won't have time to stretch your legs, you just did that walking the half mile from Ops, the 'ladies?' will be far to busy to talk to you or anyone else and you won't be waiting for the pax, they will come wether you are ready or not. If you need a number, how about 25 mins before etd?
Are you trying to prove a point? Do the LOCOs cut corners even here on the pre flight?
Which journal do you write for?
Happy New Year