I hold an FAA CPL/IR (ASEL & AMEL) if I do the flight review and IPC in a ASEL would I be current in AMEL as well
Nothing personal but yes, unfortunately you would be.
Ideally you should do your IPC/FR in the
highest category you are rated in, not the
lowest.
But in my time as a CFI I have seen many do an IPC/FR in the cheapest plane they can find rather then in their own Twin...
Instrument rating (FAA) is category not class limited so SE current = Multi engine current.
Flight review is not category nor class limited and any time you add a rating the clock resets.
What does not carry over are the 90 day landing currency requirements.
So with an IPC in a single you are Instrument "current" in a Twin but you cannot carry pax untill you've met the three T/O and landing reqs.