Just noticed a bunch of errors in the logfile... turns out that I messed up the zoom level definition of the 1981-87 aerials in the process of correcting another error. If you zoomed in too far, the map went blank. That is fixed now.
I also use that Rowan Property map a lot, and they have a nice selection, including Here maps. It's typical for me to have Boyds, Google Maps, NJ tax map, USA photo maps, and the Rowan map all open and available since I do reports of the last year in January. I'm using your maps a lot now, and putting waypoints on to show plant locations in my report like this (I blanked the plant name out, but it's not an important plant to most people anyway).Just to close the book on this, contacting HERE support to close my account. Their new pricing is too confusing to fully grasp, but from what I can tell, the first 8 days of January cost me around $7. I'm not going to miss any meals to pay that off, but it's significant - $360/year - and I haven't changed a single thing from before. I never even used half of the free map tile allowance under their old plan.
It's probably buried in the fine print but I never saw it, they said you didn't have to change anything and it would work the same. It works the same... but costs 15x more! If I re-wrote my code, I might be within the new limits, because it works differently now. But it made more sense to re-write my code... without them in it!
I'm a registered HERE developer, which is free. Their maps are not free but you get a monthly quota of free tiles. That quota is very generous IMO, and boydsmaps typically only uses about 10% of it.
Good luck with developing your alternatives!