For those that are too lazy to watch, these are:
Deelay: https://integraudio.com/deelay-review/
Surge XT: https://surge-synthesizer.github.io/
Cardinal: https://github.com/DISTRHO/Cardinal/r...
Fire: https://github.com/jerryuhoo/Fire/rel...
Ruina: https://bit.ly/39jTWQw
Gatelab / Filterstep / Panflow: https://audiomodern.com/free/
PaulXStretch: https://sonosaurus.com/paulxstretch/
Recommended by Paul Seeger via Facebook.