EHX Freeze...I hear there are various versions out there. What happened from one to the next one?

I just Googled because I was curious and saw mention of a 2019 version with a soft-touch footswitch and redesigned circuit board to accommodate the new switch. Where have you heard about different boards?

 

Are you talking about the Super Ego and the Super Ego Plus? I use them both, and I put other effects in the send/return which adds that sound to the sustained tone...the SE Plus has a bunch of effects included but I just use the filter sometimes to make it low fi.
My outboard effects on the dedicated Superego plus board are EH Mel9, C9, TC Spark Boost (for eq and a bit of dirt, great for cello sound) a TC Helix phaser (a necessary and perfect addition to the sustained note), EQD Rainbow Machine and Arapanator sequencer. (best use of Rainbow Machine I've found) I use these on Trigger usually with sensitivity set so that each note I play is sustains for as long as I hold it, then if there's something I want to capture, I do what effects That (different on each, with the superego plus you can use foot control) The superego plus also has a good sound on sound function where the new note adds to the previous for chords, and eventually the background note fades out at a speed you set...

 

I'm pretty sure he's just talking about the Freeze pedal. There have been a couple of revisions, though other than the soft switch on the latest version, nobody knows the actual differences between them.

I too have the SE+, after owning the Freeze. The effects are cheesy but I like all of the other changes and controls.