An artist's depiction of an Extended Unit Death
As opposed to network-side? The inconsistency could potentially cause a desynchronization, but it's more likely that if there is a difference, it would be that it crashes on certain setups. Certain units, like Marines/Firebats/Ghosts/Zerglings, are very stable, whereas others are not (Hydralisks come to mind specifically, as they crash on Windows 7 but work fine on Windows XP).
The primary reason for crashing is because the unit is trying to display an illegal sprite frame. This most often happens when you enable the unit, which is why issuing an order to the unit (which updates their sprite frame) fixes the issue of crashing when the unit is looked at. Some units, like the Science Vessel, will still have illegal frames if they move in a certain direction, so they'll crash the game if you're looking at them while they move in that direction. Other units will have illegal frames regardless of their facing direction, meaning they cannot be useful for anything. Finally, some units will simply crash the game immediately when you attempt to enable them, regardless of whether or not you can see the sprite.
Finally, in the case of unit sprites, they generate a rock doodad sprite somewhere north of where you enable them. If you enable the unit sprite at the top of the map, the generated sprite will be off of the map, which can cause instability issues (it may cause the game to randomly crash several minutes into the game).
So, the trick is to disable/enable the unit in a hidden area on the map (for unit sprites, an area that isn't at the top edge of the map), and then issue an order so that it uses a valid sprite image. Once it has taken the action to move (~100ms is fine), it will be fine to use for any particular purpose.
I believe in the case of unit sprites, if you check the "disabled" flag on the unit properties and then enable it in-game, the unit will not be cloaked: it will just lose its collision. If you want it to also be cloaked, you have to disable and enable it again. I use this trick (in combination with another quirk that lets cloaked nonvisioned units look uncloaked) for the player-controlled Zerglings in Dash X and all of my Jog maps as a means to see where the other players are and what they're doing without them getting in your way (they can't block you and you can't accidentally click on them).
Someone was working on an updated list of doodad states for 1.16.1, but I forget who it was and what the status of their endeavor is.