The minimum frequency must be an integer

I don't like it. It doesn't allow me to get 27.5.

Second: Please allow nearest neighbor resizing of sounds. A maximum frequency sound becomes a square wave as frequency is raised. Perhaps a "Nearest neighbor (no aliasing)" that mirrors the same option for square wave, but make sure integer upsamplings are exact.

Please allow selecting a different algorithm for downsampling. A good simple one would be box sampling - pick a few samples and average them. This should somewhat remedy the issue of high frequency aliasing with downsampling using nearest neighbor and bilinear.

Please! We can't choose 27.5! That's important! Why make frequency choice very coarse for low frequencies?