No, it is not possible to destructively edit anywhere in Lightroom Classic (or Lightroom or Camera Raw), because Lightroom never changes the pixels in the original source photo. Changes (edits) are only ever applied to copies made during some form of output/export. All edits are destructive (no matter what program you use) when saving out an edited copy. As long as you are in Lightroom, then applying a preset on import is no different than applying a preset in the Develop module as far as destructiveness goes. In both cases you can always reset back to the default (unedited) settings.

Virtual copies are useful for many reasons, but are not required as part of a regular editing workflow. You can absolutely just work on the one original source photo to your heart’s content.