What’s with the assumption of Goku needing to fire energy beams for Feedback to take his Ki? Feedback can directly touch and rip your energy out of you, as we saw with “Phil” and Malware in OV.
Further, the Omnitrix’s ability to mess with genetics (plus Master Control), means he could literally just think in his head, “Turn him into a ferret,” and then Goku would be (a Ki Using), ferret.
Edit: Also, the DNA scan by the time of OV (as seen with Whampire), is automatic and wireless. Being in Goku’s presence automatically gives him the Saiyan Sample.