Check your Merchant Offers again.
On my Custom Cash which was converted from Double Cash, I have an offer for 10% at CVS up to $25 statement credit.
This would stack if you make drugstores the top category.
Buying a $250 VISA gift card would give you $25 + $10.30 - $5.95 = $29.35.
That works out to 11.74% "profit".

My Rewards+ and original Custom Cash only have 5% for CVS up to $12.50 statement credit.