What you heard is probably correct. It has been a lot of years since I ate some lemon cucumbers. The seeds probably were well developed. I don't remember. I never ate one still green so I don't have a taste comparison.
I also love cucumbers in a lot of different ways. I think my odd ball cucumber was probably the best I've eaten. I really have a hard time comparing it to other cucumbers because it had texture more like a melon, but with a mild cucumber flavor. Because it had a fully developed seed cavity, the flesh was seedless. I have another of possibly larger size I am allowing to ripen on the vine. I pulled one last night that is more like a normal cucumber in size. I will eat it tonight. My vines are doing well and I expect to have more until fall. I'm saving seed if you want some.