Fortnite’s 13.20 update has made a very interesting change to the game, introducing portable upgrade benches. You can now find upgrade benches from chests, or just lying on the ground as standard loot. You can throw them, and they will make a fully functional workbench, allowing you to upgrade or sidegrade your weapons.
You can also break down upgrade benches using your harvesting tool. They have 400 health, and after they are broken down, they can be picked up and put in your inventory. There does not appear to be a limit on how many times you can break down and reuse the same upgrade bench, so once you have one in your inventory, you should be good. Basically, any upgrade bench in the game now seems portable, you can just break them down with your harvesting tool and bring it with you.
They do take a couple of seconds to build after you throw them, so make sure there are no enemies around before you commit to upgrading your weapons. This change does switch up the dynamic of weapon upgrade or side grading in the game. You know longer need to plan a route to an upgrade bench when you want to do it, and can just break down the first one you come across and bring it with you for the whole game. It also makes the established upgrade benches less reliable, as another player may have made off with it before you can get there.
The final thing of note about the upgrade bench is that if you throw it at your own feet, and don’t really have any room around you, you will get trapped in the upgrade bench, and will need to break it down before you can move on.