I am remodeling a bathroom and installing a new faucet in the jetted tub. The hardware set and instructions lead you to a flexible hookup (threaded SS hoses to connect the parts). The current setup is plumbed with copper- no flexible connections. It would be easier to use the flexible hose connections but the area will not be easily accessible after the wood panel is installed in front of the tub. Question is does code and/or good plumbing practice allow for use of flexible hose connections in areas that are not easily accesssed?
Honestly, you should have a removable panel there anyway. You want access in case something goes wrong and you need to repair/replace that faucet. Use the flex connectors but put that panel on with hinges or in some way that makes it removable.