standard pdifficulty
pdifficulty is not the standard.
Not sure where you've been mining all this time, but until very recently, all pools used pdifficulty 1.
In any case, Eligius is completely stratum-spec-compliant here.
The spec doesn't specify a minimum difficulty, but you'll note that the default difficulty is 1, not 0.9999847412109375, making 1 an
implied minimum.