Regarding powering, all Eventide Factor pedals need a 9V DC regulated power supply to operate properly. All of them draw a current around 330-360mA.
A proper power supply for Eventide Factor pedals should be able to deliver a current of 400mA at stabilized and regulated 9V DC.
There are 3 popular dedicated power supplies for pedals on the market. These are the PP2+ from Voodoo Lab, BBE Supacharger and Mod-Tone Power Plant. None of these have outlets powerful enough to supply Eventide Factor pedals. Not even the new ISO-5 from VL. It has one 300mA section which is 100mA short. As you mention you can use two outlets in parallel with the first three products mentioned which will work.
Power requirements for pedals change and realizing that, we at CIOKS made three brand new products which form our professional range of dedicated power supplies for effect pedals. CIOKS DC10 is able to power three Eventide Factor pedals properly along with other standard 9V pedals. The AC10 can supply one along with a AC powered pedal at 9, 12 or 16V AC, also along with other standard 9V pedals. CIOKS TC10 power supply can power one Eventide Factor pedal along with 3 other mA-hungry pedals with a maximum current draw of 300mA and 4 standard 9V battery operated pedals. Please have a closer look at the specifications of these units on CIOKS web site.
If you have other questions regarding powering effect pedals, you’re more than welcome to e-mail me directly. I have more than 18 years experience in this field.