No. If I need to support the boom (e.g. when motoring in a calm) I just pull in one of the reefing points which lifts the end of the boom high enough so that it doesn’t bash my head when it swings about.
One thing I have done is to make my halyard long enough to use as a topping lift – I take it to the end of the boom and haul away. I’m not decided whether this is of much use as the boom sits in a crutch when the tent is up anyway so I don’t really need it – bad point is that it means I have a fairly long halyard tail to get tangled up. I also thought that it might be good for getting the boom out of the way when anchored for fishing but it’s too difficult to get the sail off the boom when afloat – easier just to drop the lot in the boat.