The 2019 UA artificer's alchemical homunculus is described with a list of actions it can perform, most of which require the artificer to use a bonus action to issue the order. The actions listed are Dodge (the default when no order is issued), Dash, Disengage, Help, Acidic Spitle, and Alchemical Salve. In particular, the description makes it sound kind of like these are the only actions the homunculus can be ordered to perform:
In combat, the homunculus shares your initiative count, but it takes its turn immediately after yours. The only action it takes on its turn is the Dodge action, unless you take a bonus action on your turn to command it to take one of the actions in its stat block or to take the Dash, Disengage, or Help action.
The description never explicitly says that the homunculus cannot perform other actions, but if we take the wording literally, it seems that ordering it to perform any other action is not possible, at least not in combat - doing so will just cause it to take the Dodge action.
To add another complication, the homunculus may not be physically capable of performing certain actions. The examples given for the homunculus' appearance do not include hands, for example (emphasis added):
You determine the homunculus’s appearance, which includes wings and bits of alchemical equipment. Some alchemists prefer mechanical-looking birds, whereas others like winged vials or miniature cauldrons.
In addition, the languages section of its stat block says "understands the languages you speak", which implies that it can't speak.
So, considering both its physical capabilities and the mechanics of issuing orders to it, what other actions, if any, can the alchemical homunculus be made to perform? The "normal" actions listed in the basic rules that don't appear in the alchemical homunculus' description include: Attack (presumably an unarmed strike), Hide, Ready, Search, Use an Object, and of course improvising an action. In addition, some magic items require an action to activate (which is separate from the normal Use an Object action), or a command word. If the homunculus can perform any or all of these actions (and can be ordered to perform them), does it matter whether or not it is in combat? Are there any actions that the homunculus can take without needing an order, such as feeding a potion of healing to its master when they are knocked out (and therefore unable to give the order)?
Also, while the homunculus on its own has no bonus actions it can perform, it could conceivably be given a magic item that is activated with a bonus action. In this case, would the homunculus be able to activate the item (and again, can it be ordered to do so)?
Note: Another similar question has previously addressed the issue of the mental capabilities of the homunculus, but the answers there do not address its physical abilities or the possible limitations of the order-issuing mechanics.