First I installed AROS on a VDI disk image, connected to SATA. It wasn't easy, 64-SMP isn't stable (input.device? zune?). Once done (tweaks on the grub boot line and in the UEFI shell) I obtained a VDI I converted to RAW with vbmanage converttoraw blabla... With Rufus I wrote the RAW file to an USB stick and from there added the stick to the Virtualbox V7.0 USB filters (xHCI mode). AROS booted. See my screenshots :)