You can replicate the algorithms by using a non-linear interpolation of GF Low/High as you surface. If the first stop is the same, then the GF Low replicates the beginning of the alternate algorithm. For the graph shown, the later stops are longer, which is equivalent to a lower GF at each of those depths (and a lower GF High).
The first step would be to reduce GF high to produce the same total deco time as the iso-risk profile. By itself, that might get you very close. If not, add a GF Middle interpolation point. It shouldn't take very many intermediate interpolation points to produce a result that is the same withing measurable tolerances.
You could write the target GF's (maybe planed using something like SubSurface) per depth in your wetnotes and use the GF99 feature (or even SurfGF though less convenient) on your dive computer to implement. A GF+3m or GF+10ft feature would make it even easier, but doesn't exist.
In general, much of what makes the current GF values significantly non iso-risk is the the relatively large difference between GF Low and GF high settings currently in vogue.