From what I've see & heard...
I would NEVER put heavy gauge strings on my C64 models as the necks are thin and the non-S model (sanded down version, original spec, or close to it) has the bridge that doen't have the extra screws which secure it to the body. The bridge on mine is already lifting (2005 model year) and I have the factory strings still on it (shows you how much I play it). The S model at least has the two additional hold down screws, but, look out for that thin neck!!!
The same is true regarding the Chris Squire model; thin neck but has the two-extra screw bridge.
My 5-string has 40-60-80-100-120 DR Hi-Beams. I'd never put a 130 B-string on it for fear the neck might... It has the 4-extra string bringe, which eliminates tail-lift, but the neck is suseptable to bowin I feel if strung with heavy gauge strings.
The newer 4003 models, however, have a nich thick beefy neck. At least the ones produced in Jan of this year. I've read somewhere here in TB, from Rick5 I believe, that Rickenbacker has gone back to using a 2-piece laminated thinner neck. Anyway the thicker, beefier neck I'm sure will withstand the heavier gauge strings.
Will I try it? Probably not, mainly because I'm satisfied with what I get from the factory strings, or D'Addario EXL 170 Nickel Wound 45-65-80-100 gauge strings, which is what I have on my CS.
And yes, there is still tail lift on the newer models so I'm not sure how much that condition might be exasperatedby using heavier strings.
There may be exceptions to the rule, so I'd proceed with caution.
I love my Ricks, but they aren't the most robust instruments around and do suffer from several design flaws. So I live with it. No big deal.
Now if I could only scrape up $5,000.00 for that insainly OVERPRICED V63 Sea Foam Green Rick!
