Updating selected value in widget after changing param.Selector objects

Param
8

I tried now with panel 0.10.3 but same behaviour as before.
Here is the self-contained code example again, to prevent talking past each other (:

import param
import panel as pn
pn.extension()

class Test(param.Parameterized):
    value = param.Selector(default=1, objects=[1,2,3])
    _updating = False
    
    @pn.depends("value", watch=True)
    def update_param(self):
        # add one more number to objects
        if self._updating:
            return
        o = self.param.value.objects
        new_objects = o + [o[-1]+1]
        self.param.value.objects = new_objects
        
        self._updating = True
        self.value = 2
        self._updating = False
     

test = Test()
pn.Param(test.param["value"], widgets={'value':pn.widgets.Select}) # maybe this is the wrong usage wor a widget in this case?

Another unclear behaviour to me is, that when changing the widget value back to 2 (= the set self.value value) it doesn’t update the list.