I haven’t been able to bring up those Boss GX-100 settings image (in several different browsers), but I did download the manual. At least the parameters and ranges reflect the SE series; if not the exact algorithm structure. I imagine more resources available to the phaser in the full rack model. It was not easy to separate effects on the videos I found (with YouTube-quality audio tracks).
At the time of original posting, I was in the process of demo’-ing algorithms for an H9 Standard. It’s since become an H9 Max+Core pairing, with many more hours under the belt. I believe one difficulty with an H9 / ModFactor emulation is that the LFO waveform isn’t truly ‘quantized’ into discrete steps. Secondary modulation can add to a (triangle) waveform, but the results aren’t quite the same.
Here’s an example. You can hear the alternating high & low values of the SQUARE .wav amplitude modulation, rather than the ascending & descending ‘staircase’ effect. Close, but not all the way there.
With the original hardware lacking any MIDI sync, it’d be more accurate to deal in Hertz, and try to match that to the percentage variables. Since a Resonance parameter is featured, the FEEDBACK sub-type can help (optional).
There are many interesting variations, with switching among SHAPE and MOD SOURCE combinations. A more powerful route is to ‘split’ the algorithm simulation between two units. For example, the SE-style Flanger (with Gate) is much more believable with the TremoloPan algo in series with Flanger (in a 2nd H9). That kind of routing can also be used to bring some of that “mallet-marimba” attack to the base Phaser modulation.