Use AllStar Link & an Icom IC-705?

Well, I think I understand what you are driving at…

Let me say it this way so there is no confusion…

You can not expect to plug the radio’s usb port into a asl server and expect funcionality. There is no code in app_rpt for it through the radio’s usb.
However, I can assume you are looking for digital mode capability, and for that in asl, I would suggest DVSwitch. See the dvswitch group at groups.io

You can connect it like any other radio (audio and logic) with a sound fob and/or parallel port and I would think it is logical to assume that since dstar is a mode of the radio, it could be brought forward in the same manner if your connection and config are correct as analog to asl.

If you do connect it to asl, I would like to hear from you for a possible beta test for control of the radio through asl or the web.