I've not tried to install a jack from Harbor Freight, but I imagine you could enlarge the lower hole enough to install the jack without seriously weakening the tongue. A grinding wheel on a drill would be how I'd try it.
I wonder if the electric jacks from etrailer would fit? Harbor Freight DOES have some useful stuff, but I don't trust their quality as much as I do items from other sources.
Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH
2014 F150 Platinum 4x4 3.5L EcoBoost SCrew