Different payments for different conditions

Hi! Maybe someone has already found a workaround for this, but I think it would be hugely beneficial if Prolific would allow different payments for different experimental conditions. Creating different tasks and launching them consecutively violates random assignment (which may not be a big deal for some studies but can be for others, and is something that should be taken seriously because you don’t actually know if non-random assignment has had an influence).

For example, say I want to manipulate study-test delay. I would like participants to sign up and be randomly allocated to an immediate condition (they do study and test in one session, and get paid $2) or a delayed condition (they get paid $1 for the study session, and an additional $1 once they complete the test session). Currently, the only workaround I see is to pay a fixed $1 to everyone after session 1, and promise/pay “immediate” participants an immediate $1 bonus payment, while “delayed” participants receive the 2nd payment on completion of session 2. This solution may create issues with seemingly low payment (or alternatively make the experiment much more expensive).