How to preserve lat/lon coordinate labels when projecting data?

The way I would approach is to apply a custom HoverTool to transform it from the projection coordinates into lat/lon. Here is an example for ccrs.GOOGLE_MERCATOR (the default CRS), but for the ccrs.Robinsion another calculation is properly needed.

import cartopy.crs as ccrs
import xarray as xr
from bokeh.models import CustomJSHover, HoverTool

import geoviews as gv
import hvplot.xarray

gv.extension("bokeh")

ds = xr.tutorial.open_dataset("air_temperature")

# Setting up custom formatter
formatter_code = """
const projections = Bokeh.require("core/util/projections");
const x = special_vars.x
const y = special_vars.y
const coords = projections.wgs84_mercator.invert(x, y)
return "" + (coords[%d]).toFixed(4)
"""

formatter_code_x = formatter_code % 0
formatter_code_y = formatter_code % 1

custom_tooltips = [
    ("lon", "@lon{custom}"),
    ("lat", "@lat{custom}"),
]
custom_formatters = {
    "@lon": CustomJSHover(code=formatter_code_x),
    "@lat": CustomJSHover(code=formatter_code_y),
}
custom_hover = HoverTool(tooltips=custom_tooltips, formatters=custom_formatters)

ds.air.hvplot.quadmesh(x="lon", y="lat", features=["coastline"], tools=[custom_hover])