I actually love this approach: floating by default, tiling when you say so.

I'm yet to see a tiling WM that handles very large (>27") screens sensibly, without wasting screen real estate. Having two terminals, each 200+ columns wide, side by side, is about as useful as having a 10m long mouse cable. Hybrid floating/tiling should get more love.

I also used StumpWM (https://stumpwm.github.io/) for years, primarily in purely-tiling mode. The killer feature for me was that you (the user) define frames on the desktop, and then windows are placed into frames rather than resizing and re-jiggering everything whenever a new window opens.