I found a similar issue with the git commit log example (when filtering from initial state and clearing filter) - I guess it can be reproduced via a "heavier" example e.g. a couple hundred nodes with more frequent state changing.
There's also a stress test here which updates several hundred nodes each frame:
https://github.com/thi-ng/umbrella/tree/master/packages/hdom...
E.g. each cell shown requires 3 DOM updates per frame, so in the 256 cells config it updates 768 DOM nodes. On my MBP2016 this config runs at ~35 fps, 192 cells (576 real DOM updates) at 59-60fps