I tried burning the FreeBSD 13 beta 2.amd64.iso onto a 4.7G DVD with K3B. K3B wouldn't burn it, because it said the ISO was too large to fit on the DVD (4555 MB). I burned it to a dual-layer DVD with no problem....but I don't know how many people would have those...
I do not think we are going to address this at this point in the release cycle, considering the ISOs can be dd(1)'d to a flash drive as well.