Thank you wweich & kisolre your conversation has been useful to me and has made me consider different file versioning approaches. I definitely think this is the feature to full-fill my need in a bit of a hacky but perfectly acceptable way that works.
I think I am going to opt for Simple File Versioning with something ridiculously high like keep 999 versions. Bearing in mind that my full backup images will be a series of around 12-15 files each 100GB big and then a series of incremental images trickling in days later which may be around 2-4GB. The hard-disk is 2TB big, I figure if malicious code on the home PC modified/encrypted the backup images malicious, lets take worse case scenario; not just once but multiple times and those changes were replicated to the remote (work) location then my original image file will still be safe in the .stversions folder + the drive will probably fill up quickly if Syncthing started to create duplicate versions of the 100GB files, it filling up and ceasing to be able to create further endless versions of huge files is probably a good thing and it will obviously never reach 999 iterations of huge disk-image files which are 100GB.
I have done some testing with the file versioning and actually tested by purposively corrupting smaller sample data, everything so far is working well as one would hope.
Thank you for your time and input all, if anyone has any further suggestions I’d be glad to hear them.