FreeFileSync's Real Time Sync with LR cat

I have been trying to create a working backup system for really long.  I have tried RAID 1 mirrored systems (both hardware and software based) but these don't make any sense as they are unreadable outside of the particular enclosure in that array.  If your enclosure dies or eventually becomes obsolete you are stuck until you buy that brand enclosure again. I wanted to find a solution where my working copies would be readable from any hard drive dock and that way once I filled up those two drives I can archive them both sending one off to a secure location while keeping one onsite for easy access. 

I am running Mojave version 10.14.2.

I bought a 4 bay thunderbolt 3 enclosure from OWC and use it as JBOD.  I put two 6tb hard drives in bay A and B for my current working files (C and D are used in the same way but with a different project).  I use a Master LR catalog for all my projects unless it gets too full and then I start a new one organized by date. 

After many many failures I found FreeFileSync and tried just a regular sync between my A and B drives.  It worked great.  I didn't save it as a batch and I had some problems running it again and had to reformat my drives which was fine because I was just running tests.  The I saved it as a batch and ran Real Time Sync, and that worked perfect.  I also had the default refresh at 10 seconds but had forgotten to make it run in the background.  So when I did tests making changes to RAW files in Lightroom I got a notices all the time.  I'm thinking I can change it to not give me the alerts all the time and just run in the background.  I was afraid that the constant changes you are making to files in Lightroom might not work well with this but so far in my tests haven't had a problem.  Perhaps I will change the refresh time to be a little longer. 

My other thought was to sync hard drive A and B but to exclude the LR catalog through the filter option.  I could then set my LR catalog to back up to the B drive upon closing.  But that would mean losing work I did during any given session if something happened.

Also once a week or so I will connect a thunderbolt 3 dock and make a complete backup of the data on drives A and B and keep them offsite just in case so as to employ the 321 method. 

Does anyone have any experience or thoughts on this setup?  I have heard that it's bad to run freeware because they could be monitoring your computer but couldn't that be the case with other softwares? It seems to me that a lot of people use FreeFileSync and have had a decent experience.  There are also many other softwares that you can pay for or use the free version of that do this same thing but I don't know anything about them. 

Thanks!