Antisiphon valves downstream of reduced pressure backflow device

Is it ok/safe/acceptable to use antisiphon valves downstream of a reduced pressure backflow device(RP device)? The reason to do this is that, with the situation I'm dealing with, the antisiphon valves are already there as the functioning valves, but are at the bottom of the slope they are servicing, and thus are improperly and illegally positioned. If they are safe to use with an RP device I would rather use them, instead of replacing them with some inline valves, which would be the normal valves to use with an RP device. So whether I replace the antisiphon valves with inline valves, I will in either case be using an RP device.

Thank you all for your attention

You may get someone with more expertise that I have to answer this, but IMHO, you should be OK.

valves

You can have as many anti siphon devices in the line as you wish, as long as you have at least proper one.

As long as you use the RPZ, anything downstream of it is more or less immaterial. Go nuts.