Most of my modern sport bikes are faster in 2nd gear than any of the old Brit bikes I still ride. At 3 figure Ducati speeds, I really wouldn't want the Monroe Shocks off my Velo suspending me, or Norton Roadholder forks. Not really sure what you mean by 'rate' in the damping context with valving, (although rebound damping is most crucial of all on the rear - which surprised me when you mention having a lack of it!) It's more usual to talk about spring rate. Although I've used Girling, Armstrong, Monroe, AMC's own shock, on many Brit bikes, I've never seen traditional ones with any damping adjustment, just a bit of pre load if you're lucky.
Yes the GPz900, 1100s, and CBR1000 I rode all had nice and refined suspenders, especially the ‘plastic fantastic’ CBR, but l’m not saying most newer bikes weren’t better or more adjustable. I was discussing a W800 classic style cruising twin made to ape things like the Triumph Or BSA twins of yore. It’s just that many ‘non sporting’ models from Japan l have ridden seem to have been left for the untrained apprentice to design or select the suspension components, or were so budget restricted, or maybe they designed in poor damping to discourage riders from pushing the cruiser chassis too far?
The old Brits by comparison may have been little or no more advanced, but by dint established practice felt like they had plenty of oily damping whether adjustable or not. They can’t all have had knackered springs.