My name is Marc Apell, I work for Speedline Technologies.
I checked out the Aim web site and found the technical data sheet for the product mentioned above, http://www.aimsolder.com. They allow either a straight ramp or a soak profile so either would work for the flux activation.
The critical part is to follow the specs in terms of ramp rate, peak temp (215 C +-5 C), and time above liquidous (>183C, 60 +- 15 seconds).
The quesiton to use a straight ramp or soak profile comes down to the product your are soldering. The key is to get the whole assembly at the same peak temp (minimized delta) and same TAL for effective formation of the solder joints. One method that I have found helpful is to look at the temperature delta right before liquidous (183). You want the product to be close to a 0 C delta below liquidous right before driving the product peak temperature so that the peak temperatures will come close. The TAL will also be easier to control. If the assembly is light enough a straight ramp will work well, if you have something with some mass then a soak profile would work out.
I would suggest getting the solder spec off the Aim website and then contacting your oven supllier to work out a profile.