Adding some sort of toggle that opens new windows as a new row is certainly possible. Interesting idea to open in new row if the current column only has X windows and new column otherwise :)
This rule could also be window type specific. Eg. if the current window is a browser open in new column. If its a terminal, new row.
EDIT: Vertical tiling screenshot: https://imgur.com/g7CRfgR
meta+WASD/arrow keys to move in the workspace grid, plus a 4x4 square on my keyboard mapped to each individual workspace, hold down alt too to bring the current window with you.
meta+Q/E to resize the active window, and meta+tab is like alt-tab but for workspaces. meta+ctrl+WASD/arrow keys to swap window positions.
meta+F/T to toggle floating/tiling, useful for calculators etc. Floated windows always stay on top.
[0]: https://store.kde.org/p/1198671/ and https://github.com/lingtjien/Grid-Tiling-Kwin