Brultech's CTs are safe to run without a load.
Our SPLIT-200, SPLIT-100 and SPLIT-60 CTs all have internal burden resistor and poses no problems if left unterminated under load.
Our Micro-40 and Micro-80 CTs have no termination and will only generate up to approx 14Vdc (low current) if measuring 20A-40A.
It is true that some CTs can generate hundreds or thousands of volts if left unterminated and possibly destroy themselves due to hi-voltage arcing between windings. This does not apply to the CTs we use. Since the magnetic core of our micro CT is so small, it will saturate prematurely with no burden resistor, limiting the amount of voltage that can be generated.
It is recommended to keep the CT leads shorted together if not terminated. Also the breaker should be turned off when terminating the leads to the ECM-1240.
from the thread "CT Continuity Test". viewtopic.php?f=7&t=192&p=744&hilit=burden&sid=6489d9205f68f58e74a36a4669a5d540#p744
So, while I think that electrically speaking, switching CTs is safe, I don't think it is practical. You would need to worry about the ECM settings and it would make a mess of your database. It seems to me that it would only be useful/interesting in a fairly short time span. When you look at data from 3 months ago, how will you know what circuit was being measured?