Chapter 18 Separation close to ETS date

Can a Chapter 18 separation be initiated and completed if I am within 80 days of my ETS date? I’m asking because I could potentially be facing a Ch 18 if I don’t past tape within the next few months. Doing the math right based on monthly tapings if I fail ABCP it will right before I anticipated on taking terminal leave and about 80 days before my ETS date. Meaning I would be stuck at my unit to start the separation process instead of being on terminal leave. Yea I’m a fat body I know, literally why I wanted to get out in the first place.

Edit: While I do appreciate advice about SFL Tap and everything else. I re-enlisted 4 years ago knowing and planning on getting out since then. Wife is a nurse practitioner with va disability. I’ve already completed TAP (Tier 1), working my BDD currently and have a school & job lined up already. So as far as being prepared for civilian life I’m already set on that part. Just trying to get a better understanding of a ballpark timeline of what people seen. I simply was fit had kids and struggled with tape since then. Want to mend my relationship with food and the gym without crash dieting and having to do it on the Army’s timeline. I am no longer a fit for the army and the army is no longer a fit for my life goals (pun intended). I do still appreciate everything the army has done for me but it is time to hang up my boots.