Honestly, I'm surprised this is even a question. If you've got decent add-to-cart volume but a crap checkout rate, capturing the email earlier is a no-brainer. The whole "but they might bounce" fear is overblown. You're already losing them anyway-what's the worst that happens? They don't give you the email and you're exactly where you started.
I've done this on a few stores. Key is making it feel like a natural part of the flow, not a desperate popup. Embed it in the product summary or as a pre-checkout step that says "Get your custom quote" or "Save cart for later". Then feed those emails straight into Meta via CAPI. Suddenly your abandoned cart sequences actually have someone to target, and you can retarget with ads that aren't just guessing.
Everyone in that thread saying "only if it's not a trap" is spot on. But don't overthink it. Test it. If conversion rate drops? Roll it back. Chances are it'll pump your email list and unlock retargeting without killing purchases. You're already bleeding sales from cart abandonment-this is a tourniquet, not a amputation.