How can I change PropertyGroup properties (IntProperty, FloatProperty etc) after Operator executed using the PropertyGroup? Blender 3.6 Python 3.10.12

Question

The question is: how to make changes in last action menu affect the operation with properties are passed in, like if I change them in MainPanel menu before the Operator execution? I want to make like dynamically changing properties.

I have my PropertyGroup:

class FBGenProperties(PropertyGroup):
    root_subdiv : IntProperty(
        name = "Chains Amount",
        default = 3, min = 1, max = 100,
        soft_min = 3, soft_max = 20,
        subtype = "FACTOR"
    )

    bone_length : FloatProperty(
        name = "Segments Length",
        default = .1, min = 0.001, max = 100,
        subtype = "DISTANCE"
    )

Also the Operator:

class BonesGen(Operator):
    bl_idname = "object.bones_gen"
    root_subdiv : IntProperty()
    bone_length : FloatProperty()

    def execute(self, context) -> set:
        self.obj = context.active_object
        self.selected = self.obj.select_get() if self.obj is not None else False
        props = self.obj.FB_gen_props
        self.root_subdiv = props.root_subdiv
        self.bone_length = props.bone_length
        
        # I create this cylinder just for testing
        bpy.ops.mesh.primitive_cylinder_add(
            radius = self.root_subdiv,
            depth = self.bone_length,
            location = (0, 0, 0),
            rotation = (0, 0, 0)
        )

        return {'FINISHED'}

Panel, where I can executes the BonesGen Operator from:

class MainPanel(Panel):
    bl_space_type = "VIEW_3D"
    bl_region_type = "UI"

    def draw(self, context):
        layout = self.layout
        obj = context.active_object
        selected = obj.select_get() if obj!= None else False
        name = obj.name if selected else ""

        layout.label(text="Active is: " + name)

        if name != "":
            props = obj.FB_gen_props
            col = layout.column()
            col.prop(props, 'root_subdiv')
            col.prop(props, 'bone_length')

            layout.operator(operator = "object.bones_gen", text = "Generate Bones")

And following line in register() to make every object has my FBGenProperties properties:

bpy.types.Object.FB_gen_props = PointerProperty(type = FBGenProperties)

The question is: how to make changes in root_subdiv and bone_length properties (FBGenProperties) when operator executed like if this properties was an operator properties? I want my changes in 'last action menu' affect the primitive_cylinder_add() operation (any operation properties are passed in actually) like if I change them in MainPanel menu. Whatever help is offered. Thank you!