Here are two near random thoughts (as if you don’t have enough to work on already) inspired by the recent Sticky Tape algorithm, the recent Artifakt pedal by Source Audio, and the recent renewed requests for various Polyphony tunings.

1.  A Ragtime Piano tuning/mode for Polyphony in which many of the notes across the whole note range are as out of tune as an old piano.  This might be various tuning micro-offsets mapped to each note in a predetermine manner.  This might also include multiple micro-offsets for each note to mimic multiple out of tune strings sounded with each piano key struck in the middle to upper register.  Alternatively, this effect might be created by calculating and applying some complex or random micro-offset(s) in realtime as notes are sounded/detected.  Here is a YT link of the Maple Leaf Rag being played on an out of tune piano specifically because that piano was out of tune:     https://www.youtube.com/shorts/WSbtiUiYpYw?feature=share

2.  A random latency generator that could be included as one feature of a lo-fi themed algorithm.  This would provide enough unpredictable latency to trip people up as they play to thereby yield unexpected results.  Naturally, this could be combined with the aforementioned ragtime piano tuning mode, some static/noise, and/or a band-limted EQ setting or two.   An algo like this might pair well with Sticky Tape, Mangled Verb, Vintage Delay, or Head Space, or some such.