How do I unlock SPARK units without doing the Shen's Last Gift mission?

Question

After roughly 20-30 hours of blindly playing XCOM 2 and seemingly doing pretty well, I ran into a situation where I could not prevent the Avatar Project from being completed (I had no radio comms, because I didn't realize I needed them and I was on the 2 week timer before Game Over and the nearest facilities were 3 uncontacted regions away...).

Long story short, I had to start over. I did manage to complete Shen's Last Gift on the previous playthrough and the SPARK unit I received was immensely helpful, but I really do not want to complete that monstrous mission all over again. I noticed there is an option to not include the DLC missions when starting a new game, and that you are able to access all DLC content without doing them, but it didn't say how. How do I unlock the SPARK units without doing Shen's Last Gift?

Answer 1

The SPARK units are DLC units from Shen's Last Gift DLC. They can only be unlocked after the Lost Towers mission. If you disable the mission in your campaign, they can be built after researching Mechanized Warfare.

Source: personal experience

Answer 2

While I doubt this will make you do the mission again, there is a way to make it a bit easier. This is something i noticed and played for a bit, though I don't know the details: both Sparks and Shen are priority targets, meaning the enemy will try to kill them before your soldiers. I noticed this when I first got Sparks, the turrets would always try to get him and when fighting the sectopod. Julian focused Sparks like hell until I got it out of sight from Julian, making him go for Shen.

Since Sparks can't use cover he is usually the focus on the enemy (easier target). From what I could tell, this priority is not like the decoy where if the enemy sees Sparks/Shen they will always go for it*, but you can put your soldiers in riskier/flanking positions (don't leave them too exposed/open to flanks, they will get targeted).

*As I said, Julian focused Sparks like hell, until I sent Sparks behind a structure. What happened then was that Julian focused exclusively on Shen, save for when he stumbled upon a flanked soldier while going towards Shen. After that shot, Julian basically surrounded himself by my dudes while trying to kill Shen. Weirdly enough, while doing this Julian had the chance to kill Sparks with 1 shot (3 hp left), but ignored him (he needed at least two shots to kill Shen at that time).