As for consume_on_start_of_layout, How about this
As for consume_after_purchase, Do you say this?
Your consume on start of layout won't work (I tested a few variations of what you are doing and it did NOT work, only the 1st consume action work the rest did nothing, product wasn't consumed), because the way C2 processes conditions, the empty one between product1 and product2 has no effect. Events run simultaneously unless they are tiered.
In your example, event #3 ONLY runs after #2. But #4 and #5 runs also at the same time (in that tic/frame) as #3 after #2.
Definitely just put
#2 On store listing success = Consume 1 & wait 0.1 & Consume 2 & wait 0.1 etc
Because if there's no product, consume doesn't do anything. For consumable/unmanaged IAPs, there's no drawback of a negative result.