Yes you can use one of those adapters but will need to perform a means of waking up the P30H prior to taking the exposure and also make sure the shutter is set to long latency.
Here are a few options:
1) Use of Primary Sync Cable's @ $89 (requires MF to mini adapter for all PhaseOne mounts,except V-Mount)
2) Use PhaseOne Wake Up Cable @ $110((requires MF to mini adapter for all PhaseOne mounts,except V-Mount))
both above will require this adapter:
Multi conn. to mini jack adapter cable (Item No. 50300144)
3)The Kapture Group Single shot cable $395 (**note can be ordered in a short config w/ mulit conn. built in)
As far as the adapters go, I do not know anyone with direct experience with the ECO adapters. I have suggested them but never have seen any feedback on how they are built and or ease of getting them here in the US.
I have heard some using the Leaf Adpater with one of the above methods mentioned above.
Lance