there seems to be a bug in 2RuleSynth (v1.1) with Reaper. Since there are no arrow-buttons to browse presets, I tried Reaper's preset browsing function. That would work in principle, but the preset name in the synth do not change accordingly. Also a preset I saved myself does not appear in Reaper's drop down menu.
However, when I chose 'Program 1' (as opposed to 'Preset 1') from Reaper's drop down menu, Reaper crashed reproducibly on my computer (Win10).
Sorry, I cant add screenshots here. PM me, if you need them.