PrusaSlicer to OrcaSlicer

Yes. OrcaSlicer opens a PrusaSlicer file as geometry only, so convert it first to bring the settings along.

Does OrcaSlicer open the file without converting?

The geometry loads. The settings do not: OrcaSlicer says The 3MF is not supported by OrcaSlicer, loading geometry data only. Converting writes the settings in OrcaSlicer's own spelling.

What carries over?

Every PrusaSlicer bed becomes a plate. Every filament carries. Modifiers, negative volumes and the other volume roles keep their roles. Supports, seams and fuzzy skin paint keep their meaning. Colour paint is decoded and written again in OrcaSlicer's form. Object and part settings are translated key by key.

What gets dropped?

Layer ranges. The Changes panel names each one, for example Layer range / not carried / preslice does not write OrcaSlicer layer ranges. If a model cannot be split into parts, it stays as it was and the panel counts it as N objects left as it was. Other shared losses are in what a conversion cannot carry.

Which OrcaSlicer settings will not come from my file?

About 460 keys OrcaSlicer declares have no PrusaSlicer counterpart, such as adaptive_pressure_advance. Each takes its value from the OrcaSlicer printer profile you picked, then from OrcaSlicer's own default where that profile sets nothing.

Can I convert it back?

Yes. See OrcaSlicer to PrusaSlicer.