I have been thinking about this. Why hasn't JYPE seriously evaluated having full-English songs for Day6 to be used to get more international ($money) brand deals, product placements, and sync licensing (for Film, TV, video games)? This was cool for Day6 to work with Undertones. I can imagine them working with more international clothing brands like Zara and Uniqlo (maybe even getting some of their songs played in the stores too).
Just by being a Pop/Rock group of musicians, they have some built-in international appeal. The English in their Korean and Japanese songs sound more effortless than a lot of K-Pop groups. It doesn't make sense why "Shoot Me", "Baby, It's Okay", "Days Gone By", "Where The Sea Sleeps", "Everybody Rock", "I Have Loved You", "I Like You", "Letting Go", "You Were Beautiful" don't have English versions. These songs emotionally connect super effectively. Plus the guys could write the English versions themselves. This would be very cost effective. Based on "Congratulations" and "Zombie", I conservatively give Day6 a 60-70% chance of writing effective English versions compared to whatever resources JYPE used to write Itzy's English versions.
Approaching Day6 as a international group would garner more respect for K-Pop having actual musicians who can sing and harmonize better than most guy groups out. I put them in the special tier with Mamamoo and Red Velvet because of this. Day6 are doing what K-Pop guy groups and a lot of current American Rock bands aren't and that gives them additional value that JYPE has undervalued up to this point. If they do effective English versions, that will add even more value to JYPE.
JYPE could also get additional respect for having capable singers. Newer K-Pop listeners aren't going to know of 2AM and Jun. K. (of 2PM) because the songs weren't prolific enough. Jihyo is like the only internationally visible singer right now.