How much mass too much for a Rega RB-700?

I hate installing and aligning cartridges, so I tend to optimize a pool of mid-fi decks for the individual cartridges that I use. I set up a P3 specifically for a Zu DL-103 with a Groovetracer 163g counterweight. This adds about 5 grams more than these tonearms usually see at the headshell end, and about forty or so more at the other end. I was thinking about moving the Zu to my P5 to see how much I can extract from it, however, this is one of my "pet" decks that I wish to keep forever and do not want to damage. Would any of you EXPERIENCED REGA OWNERS worry about this much added mass damaging your bearings over time, especially if you might go back to a more conventional setup much later?
I have used aftermarket counterweigths on my P25 for years. Never had a problem nor do I think I ever will. No worries, IMHO...