I was reading the body language post recently

Let's Talk Body Language : marriedredpill (reddit.com)

tried the scapula back and down positioning and damn does it make a difference, now my question is pretty basic (hence askMRP), if the post were live I would have commented this question rather than posting.

I am able to do this but it seems to take a bit of effort and I cant hold it for more than 5 mins at a time.

The idea is that this should be my default pose (which is great as it instantly fixed my posture) - do I get stronger at this over time to the point I am pretty much always in that position?