What is the purpose of oversampling1x and oversamplingNx?

My setup sounds pretty good. Dac is Eversolo A6. Amplifier is Denon 1700ne. But I have a question, why when playing Dsd64, Roon still displays sinc-short instead of poly-sinc-guass-long?

This was kind of answered here

… but he is playing native DSD ….