dnd 5th – Are Homunculus Alchemical Companion creatures and 2019 AU Artificer Defender-creatures receiving lifejackets?

In the Unanathed Arcana update of May 2019, two of Artificer's four options may invoke constructions as companions: the alchemist invokes an "alchemical homunculus" and the Battle of Smith invokes a "ferrous defender".

Unlike the gunner's turret, which is a magic object, these companions are considered creatures and there is no text that specifically says what happens when they are zeroed out. If they die, to revive them, you have to spend some time for spells. I would therefore like to know how easy it is for them to get killed in combat.

If any of these constructs are reduced to zero health, does it die immediately or does it start throwing save throws as a player character?

5th dnd – What can the artificer alchemical homunculus do outside of the fights?

This answer is based more on the interpretation than on the rules as they are written. The first thing to note is this:

The homunculus is friendly with you and your companions and obey your orders.

The second thing to note is this: the mental statistics of the alchemical homunculus are …

Int: 10 WIS: 10

For comparison purposes, these are the same mental statistics that a communist possesses. This means that your Homunculus is about as intelligent as a typical human being.

So, you have a tiny and flying construction that is about as smart as a typical human being and that obeys you to the best of one's abilities. This makes it significantly smarter than a familiar (the smarter has Int: 3).

So, yes, I would certainly say that it strongly supports the idea that your Homunculous can understand how you "signal". In fact, I said it strongly supported the idea that a Homunculus could be given and executed without problems. In terms of "difficulty", if a random player could understand how to do what your homunculus tries to do, he should also be able to understand it.

dnd 5e – What is the good calculation for the hit points of the Homunculus for the 2019 UA Alchemist Artificer?

Since no parenthesis or other mathematical indicator is given in Points of damage section of the Homunculus statistics block,

Life points equal to five times your level in this class + your Intelligence modifier

translated directly into "HP = 5 * [your level in this class] + [your Intelligence modifier]", which means" HP = (5 * [your level in this class]+ [your Intelligence modifier]", because of the order of operations.