It amazes me that PCGS attributes these as an FS-901. This 65RD sold for $505 in 2017 https://coins.ha.com/itm/a/1252-7152.s And this one sold for $288 in 2022. https://coins.ha.com/itm/lincoln-ce...-45019.s?ic4=ListView-ShortDescription-071515 Yes they are the result of an aggressive die polishing.
Floating Roof and no FG are the result of an overpolished die. It is not a variety, it is not a mint error. It is just a late die stage of that particular die, but could also happen on other dies if they are overpolished.
I have no problem with the type to get a variety, thing is I see them nearly weekly. The price is ridiculous.. The thing about this variety is it has earlier die stages one of them has a major die clash, maybe even an early capped die. Something caused the over polished die.