when you say you are, “not trusting my life to the carbine in daily combat and statistically am extremely unlikely to ever need to actually use it for HD”, you should understand that a self defense weapon is like a life boat on a sinking ship, or a fire extinguisher in a house fire - you may not ever need it but if you do need it, nothing can take it’s place…
now, I’m not of the opinion that you need a $500 optic on your carbine for “serious use” but you do need to have an absolutely 100% durable and reliable primary method of aiming the gun. without a “trusted” optic, that is your iron sights. FYI, the optics you have asked about are not considered “trusted”…
realize that people continue to use irons sights to very effectively kill other people in combat even today, and in fact, some people even prefer irons for whatever reasons when their life is on the line.
your rifle probably has a front sight base (triangular sight tower)? if so, good, you have one of the best. if not, do you have rails or a railed gasblock?
if rails, I prefer a fixed front sight like the Daniel Defense. it is inexpensive and robust and won’t interfere with your sight picture regardless of what other optic you choose.
if you prefer a folding sight, someone already mentioned the Magpul Mbus. good kit, inexpensive, but as I said, I prefer fixed…
does it have a rear iron sight, either fixed or folding? if so, good, you have almost everything you NEED to keep the bogeyman at bay except a white light. this is for identifying things you DO want to shoot from those you don’t. having it attached to the gun is a pretty good idea as it is really hard to shoot a rifle one handed if you don’t know how.
on a rifle that I (and especially you, at this stage of the game) will be relying on the iron sights as the primary sighting system, I prefer a fixed. again, the Daniel Defense fixed 1.5 rear sight is my favorite. all previous conditions apply. you may not, and feel that a folding sight is best but make sure you get a good one.
a good folding sight is going to be more expensive than a good fixed but allows you to fold it down (duh) to fit under magnified optics. Troy is the gold standard but expensive. Magpul Mbus, as mentioned, about half the cost but still reported to be pretty good.
fwiw, I have both but only run the Magpul under a 1-4 magnified optic, as this is not my immediate action/close quarters gun and on this rifle, the Mbus is good enough for me…
if you intend to run a Red Dot Sight (Aimpoint or whatever) then a folding sight is not necessary and many people (me included) run a fixed rear sight with an Aimpoint.
most folks prefer a lower 1/3 co-witness rather than absolute. this simply means that if you look through the RDS the alignment of the iron sights will be in the lower 1/3 of the tube leaving the red dot floating above them. they feel this gives a less obstructed view through the optic tube. I agree when using my Aimpoint mounted rifle. - exception - I run a Troy folder behind my absolute co-witness Eotech on my “fun” gun.
so back to your question about the two optics you have listed, choose the one you like best for whatever reason - price, availability, whatever… many people have tried and like the Primary optics but I have no experience nor have I heard any opinions on the other you have asked about. that may be a clue…
just remember this, neither should be considered your “primary” sighting system on a rifle that you may need to defend yourself with. if something goes “bump” in the night, and you have time to arm yourself and activate this optic, and it works, well, fantastic! but I would not depend on it. and I would probably not even activate it as one of the problems of a cheap optic is maintaining zero and you cannot miss fast enough to win a gun fight…