Using 2 WD ex-hd's with same software

Hi, I hope I’m doing this right as it’s my first time posting for help. 

My problem is, I would like to buy a WD 1TB My Passport Ultra USB external hard drive to use along sid my WD My Book, but from the reseach I’ve done on YouTube and asking other people I’m a bit sceptical.  I just recently bought the WD My Book which has the password protection software installed on it, and some people (even a WD support staff) told me that using a USB ex-hd with the same software very seldom works.  Has anyone here used a WD My Book with a WD My Password USB ex-hd on the same computer and it has worked okay?   

I’d assume that even if one person posts that they do this it still may not work satisfactorily with you.

I got hot-and-bothered when I realized I (likely) couldn’t have SIMULTANEOUS - CONTINUOUS back-ups on a 1 TB MyPassport and a 1 TB MyPpt Ultra - BUT - I just simply Enable One-at-a-Time and it takes very little effort to Dis-able the first in WD Software and Enable the 2nd and let the 2nd catch-up with updates. Then Disable #2, and re-enable #1.

IF you’re away and lightning hits Doesn’t it seem Really Risky to have BOTH Drives active, anyway?

The real frustration is Not being able to attach Drive #2, catch-up, and then Remove it from the computer - WITHOUT shutting down the computer. More than one of us get “Drive-in-Use” when attempting Safely Remove Hardware and the only Moderator Reply was no solution.