Is there functionality to have multiple glyph sizes in a legend?

I am currently building a scatter plot in Bokeh. One of the attributes of the data is displayed as the size of the glyph, so I would like to create a legend that shows glyphs of different sizes. Is this possible currently in Bokeh? My previous workaround has been creating a seperate plot to use a makeshift legend, but its pretty annoying overall.

Not presently, see https://github.com/bokeh/bokeh/issues/2603 and linked PRs for latest status. TLDR still waiting for someone with bandwidth to implement. You might leave a comment there describing how it would help your use case.