Hi Becky,
Just wanted to let you know that it CAN work
I'm thrilled to say I've finally finished my synopsis and yes, it basically uses signposts such as 'at this point we return to -- childhood' or 'meanwhile in 'name of place'etc... Good luck. Always get someone else to read through it before you send it out.
Re the length of synopses, I don't think it is quite as clear cut as always one page, but if you provide what is asked for on submission pages you can't go wrong
in theory....
(Yes, I've just learned how to do smileys