How to anchor specific objects based on if they were previously anchored?

Hello everybody, this is my first post so I am sorry if the formatting is wrong.

I am trying to make a "Time Stop" script, basically it would freeze(just anchor) eveything except the player who press F and called the RemoteEvent. What I am trying to do is to anchor everything except the player, and then unanchor ONLY the objects that were previously unanchored(don't want the baseplate falling off). I am relatively new to coding so any help would be appreciated.

My code so far:

local StopTimeEvent = game:GetService("ReplicatedStorage"):WaitForChild("StopTime")
game.Lighting.TimeStopScreen.Saturation = 0
local TimeStopStartSound = game.Workspace.TimeStopStartSound
local TimeStopEndSound = game.Workspace.TimeStopEndSound

StopTimeEvent.OnServerEvent:connect(function(player)
    TimeStopStartSound:Play()
    for count = 1, 5 do
        game.Lighting.TimeStopScreen.Saturation = game.Lighting.TimeStopScreen.Saturation - 0.2
        wait (0.1)
    end
        wait(4.5)
        TimeStopEndSound:Play()
    for count = 1, 5 do
        game.Lighting.TimeStopScreen.Saturation = game.Lighting.TimeStopScreen.Saturation + 0.2
        wait(0.1)
    end
end)

Basically the player presses F on a LocalScript, which calls a RemoteEvent that makes some fancy effects using sound and color, and then would freeze everybody for 5 seconds.