Am wondering how SHA transfers from the airport work when part of the journey includes a boat?

Thinking of visiting Railay (which has a couple of SHA++ hotels) but if you book the Test & Go package will they pick you up from KBV, drive you to Ao Nang and put you on a boat to Railay? Can you book the transfer independently from the hotel? Where and when would you do the RT-PCR test?

Will we be given RT-PCR test on arrival?

Do we need to purchase the test & go package with the SHA plus hotel (which cost $160 with airport transfer and RT-PCR and AKT test) or just SHA plus hotel and airport transfer separately?

Please advice. Thank you! 🙏🏻