PFLP was always super opposed to a two state solution until the turn of the century and then a decade later went back to one-state, and only started toying with running elections as part of a united front strategy with DFLP and other Marxists in '04, that fell through though.

DFLP did split during the time leading to Oslo over approval of Arafat and the peace process. Though the ideological core left and joined a front with the PFLP until the secretary general left the party and joined the capitulationists, letting the party heal in the process.

So essentially no matter what splits happen between PFLP and DFLP, they have never really been at odds over engagement in the two-state solution. When PFLP was entertaining a limited form of parliamentarianism, the DFLP was more or less inactive. Their initial divide seems to be just different camps. Not dissimilar to how some separate regional communist parties in India with separatist views would work alongside the Naxalites even if they didn't technically organize together.