Long ago, there had been another nearby 1520 station, a daytimer called WVOB from Bel Air MD. Word was that they and WCHE got stomped in their coverage areas near sunset by WKBW. Of course, that would be even more ghastly during winter.
(Up on Long Island, the closest xmtr to the DXing den was 1520 WTHE, which underwent the same fate from KB.)
Plus, if they're doing okay with what they've got -- in their own provinciality -- why would they want to reach Philly? And as David Eduardo said, any power increase or directional changes would have been done long ago.
The old WPEN 950 can testify about the wisdom of adding all those towers and increasing the power. It seems the more they did to upgrade, the worse the ratings got. WCHE is even more perilous, being that high up on the crowded part of the dial.
Nothing personal, A-Train. I've enjoyed the distant stations myself for decades. But any further shoehorning of AM station signals in the crowded northeast isn't in the cards. Quite recently, in fact, a 1510 station two counties' north OF NYC went dark. Your Grundig and Tecson will have to do the job vis-a-vis. Consider yourself fortunate that WCHE is still on the air for you to enjoy, hi.