I have used two Transcend 1GB DOMs (plug into motherboard IDE socket) in two pfSense boxes without any trouble for nearly four years now.
I know its a known issue that a lot of SSD do not work in PFsense becuase it constantly writes to the same sector over and over
You have an authoritative source for this knowledge? This behaviour is provoked by particular packages? It doesn't seem to happen on my systems!