That component is not built on Konva though. Canvas has long been known to be the perf endgame for web, see google sheets etc .
It is Konva. You can inspect it in Dev Tools.
If GP is like me they were probably thrown off by the fact that the formatting menu is just HTML and only the cells themselves are in a <canvas> element
Unrelated tangent, but $300 for non-commercial use with limited features... wow!