There is probably a good market for some smaller-framed F1 hybrids if you cross with smaller bulls from good beef breeds. I know there are some MG bulls who are in the 3-frame range, as there are some Aubrac bulls that are the same, too. Both crosses would produce some nice F1 females and/or nice freezer beef for your family and beef buyers. You could probably also get a non-lowline Angus bull from a guy who's been breeding for smaller frame and do just fine ... and ... possibly reclaim some of the lost frame you had with the mini-herf sired calves.
And, if you want to go do something really interesting, look into Mashona bulls. There would, probably, be an internet market for a lowline/Mashona cross bulls and F1 females (iow, you might not be able to sell them locally by word of mouth, but put up a website and drive a little traffic, and you could have a winner ... if, of course, the lowlines are good cattle and the Mashona bull you find is also a good one).