So under CPPSBAM, every time I point my miners to a new eligius address... my old address will effectively be an 'inactive miner' and although the EC credit is there - it's effectively lost to me unless I point some hashing power there again??
That would be correct.
As long as that is the case, perhaps we should take another look at MPPS? The only reason we went with SMPPS AFAIK was because it allows mobility between addresses.
It would be in your best interest to use the same address (and most do) to ensure steady payouts, even under the existing system.
Why? It should make no difference under SMPPS.