At a cross roads. Do I scale with these numbers?

I’m at a cross roads and need external opinions !

I want to scale my newsletters using meta ads (I cant scale referals anymore)

~> would you scale A, B or both if you were me using meta Ads?

Newsletter A

44k subs, 40% open rate.

Growing at 6%/month,

~> churn around 3% so net +3%.

Blended CAC: $0.154
Meta CAc = $0.8
Referral CAC= $0.07 (can’t scale this anymore)
Net monthly rev: $1,300
RPM: $18.47
LTV:CAC: 6.4x

Newsletter B

8,500 subs, 40% open rate.

Growing at 10%/month,

~> churn around 4% so net +6%.

Blended CAC: $0.1775
Meta CAC = $0.8
Referral CAC = $0.1 (can’t scale this)
Net monthly rev: $500
RPM: $36.76
LTV:CAC: 8.3x

Would love to know what you think of these numbers? And whether you’d scale

TIA