Once you get over a handful of known examples I think the demand is more important than numbers available. Open 3s, 1926MEs or F164As might sell as you point out, but there is virtually zero interest in things like F175 & F176 unless they are in better grade. i.e. the number of serious variety collectors might be more limited than you think. I've tried listing a few low grade items of the latter two over the past couple of years with limited interest. They have always had to relist a few times before selling for opening bid. I sold one a few months ago, but given that had been relisted a few times threw the rest in the scrap pile and they went to the great pot in the sky once lockdown was lifted. The numbers were 4 175s and 2 176s melted. I might have a couple more that were recently acquired in a bag of pennies, but won't be busting a gut to seek them out. When you get a couple quid at most after costs, it ain't worth it.
Just as when Pete got his 1890 penny the other day from me. That had gone round a few times as well - advertised as the variety, but b****r all interest.
I recognise that the number of daily visitors to my website is insufficient to provide too many sales, so wouldn't list them there in any case unless higher grade, but when ebay with it's worldwide reach and seemingly limitless numbers of un-discerning collectors also fails to inspire, then it's worth questioning the breadth of interest in much other than a decent example of all dates. Just an observation.