I buy quite a lot of computer equipment and accessories online, but sometimes due to time zone differences I’ve had a number of failed verifications, simply because I’ve been asleep and have not seen/heard the notification for the verification message. Some companies record the payment but seemingly don’t contact Monzo for verification immediately.
is there any way around this other than placing orders and then waiting for verification with a large jug of coffee to keep me awake? 
Buying from other merchants that take payment there and then will solve your issue.
Never really known a company take payment details but not process it until some unknown point in time.
The only time I would have come across payment being taken at a later time would be when a pre order was made. In that case they may take payment just prior to shipping but I would usually see them at least carry out an active card check.
Yes, I’ve certainly not encountered this until recently: normally it’s make a payment and get the challenge immediately.
Same. Even orders where the I’m not actually charged until later usually complete a verification check/active card check immediately first.
It may well be as @PeteMcD suggested - it’s being seen as a pre-order. A lot stuff I buy is either very new to market or something like a Kickstarter pledge. Maybe I need to buy something else and test the theory 
This seems just wrong. Payment processors giver the merchants options to do pre-authorisation then take full amount later.
More like what some shops do when you order clothing for say £100 and you don’t see it immediately appear or it appears as pending but full amount charged at dispatch. In case an item is out of stock they just make adjustments before collection instead of issuing refunds.
Your sellers are a bit dodgy doing that.
Even with pre-orders you authorise at time of the order, then they are able to collect full amount when they confirm the order and dispatch with no further action needed from customer