I know this is a few days at this point but Bolero has been in active development. All development work was done on the now deleted streamrendering and v0.24 branches. Version 0.24 was just published today: https://github.com/fsbolero/Bolero/releases
https://fsbolero.io/
Unfortunately, maintenance seems to have stopped since Jan,
https://github.com/fsbolero/Bolero/releases
(I tried creating a sample project on Linux which didn't work to begin with)