You have the solution! According to this NOCO Genius 3500 User Guide, the "12v Repair Mode" has a fixed 16.5v 1.5A output. That is 4.125 volts per cell. So, you're in business and can ignore the workaround discussion above.
You'll still have to watch it and unplug to ensure you don't overshoot your target voltage.
Please do make sure that your DVM is properly calibrated. The cheap (even free) Harbor Freight DVMs are useful, but some I've tested have been off by as much as 0.25v when reading 12v.
BTW, how are you getting the battery to the car? You might check the regs.
Edit: The name that NOCO Genius 3500 assigned to that mode is interesting as Repair Mode seems have been designed not only for attempting to jolt lead-acid batteries back to life, but also for 4S Lithium Polymer or Lihium Ion (https://www.differencebetween.com/difference-between-lithium-ion-and-lithium-polymer/). I guess they wanted to make sure that someone would not confuse names and inadvertently use it for LiFePO4 batteries, which would be disastrous, so there is no use of the word "Lithium" in that Repair Mode's description.