btw..internet has lot of low quality/misinformation about Pinephone USB-C port with Pinephone keyboard.
I think I only trust this measured information, in short:
"So the only thing to worry about is to not connect anything to phone's USB port when keyboard's USB port is occupied."
original source: https://xnux.eu/log/#072

So it seems that it is safe to use Pinephone Keyboard with Docking Bar (in phone's USB-C port), if you don't charge same time. But make your own decision and don't blame me (or writer of original blog post) if something happens with Maemo Leste.

And Leste should support Docking Bar in lower level, but there is not any upper level (automatic detecting and GUI support) yet.