So why not use the EU-US conversion agreement to obtain a US private/instrument/multi and then do the abbreviated commercial-single and/or commercial-multi?
The unrestricted private/multi only requires passing a single 40-question US knowledge test, code PEP, together with a flight review with a US instructor. The unrestricted instrument requires a single 40-question US knowledge test, code IEP, and a choice of acclimatization training with a US instructor in the US or 50 PIC hours of instrument flight time (reduced to 10 hours if done in the US), followed by an IPC which can be done with a US instructor. The instrument flight time, as an alternative to acclimatization training, can be done in simulated instrument conditions with a safety pilot.
This also reduces testing with a US DPE to the practical test for the commercial.
The EU-US agreement doesn't apply to licences granted by the EFTA states.