Considering switching to XLR cables,

The Kubula's are $1250, it would be surprising if any much lower priced interconnects such as the $188 Arcadia's on your list would be better than them, even if your pre "might" prefer an XLR cable, but ghdprentice allegedly debunked that theory above. You never complained about the sound you are getting, but you could first just try the fascinations in XLR and compare yourself- The Music Room has them and if you notice no difference send them back for credit. 

But if you wanted to try Zavfino I would suggest try their next up level cables: Fusion. They are on sale at less than half of what the Fascinations are. 

Or try those highly regarded Veritas many are recommending? 

Of all those cables in your list I only have heard the Triode Wire Labs, an XLR set are currently lying on my floor unused, too polite for my tastes. I do have several Zavfino Silver Dart power cords- darn good for the money. 

No words from us are going to let you know which you will prefer, but let us know the outcome. 

I like the positive lock of XLR connectors

I have had XLR's for years and years, and I only just had to purchase an RCA set for the Coincident Frankenstein 300b amp I just got. 

I now prefer the tightness of the RCA over the XLR connection- It always bothered me how XLR's seem loose fitting- I can still wiggle them in their sockets, even though they are "clicked-in". And in some cables the male end of the XLR does not even have a slot to click in, like the Neutrik's on my Nordost Tyr2's, so they are much looser than most RCA's.