Seems that Ifoflex is positive to positive. This is from a post by another APUGer:

Stephen Frizza

01-18-2013, 04:44 AM

Ilfoflex when processed via RA-4 reversal is the most promising pos to pos process i have tested, So much so that this year I am looking into converting my Ilfochrome processor to an ilfoflex reversal machine. The great advantage over the process compared to Ilfochrome is better contrast control via manipulation of the first developer