I've tried lighter gauge strings, but it just didn't work for me. I need a higher tension feel from my strings for my plucking hand. And honestly, I didn't notice any difference in tone between lighter gauge strings and the gauge that I'm comfortable using.
Granted, the difference in gauge between the strings I prefer and the lighter gauge strings that I tried weren't markedly different.
When I started playing basses with a low B-string I used a .130 gauge, but for the past few years I've been using a .128 gauge. I honestly haven't noticed any difference in feel or in tone.
I even once went down to a .125 B-string when I tried Infeld Superalloys. Overall they had a different tone than I was used to, and it was a really great tone IMO. However they feel too low tension for my needs.
And in regards to hearing more of the note's fundamental, once I switched to GHS PWs I've noticed a lot more fundamental compared to when I used nickel plated roundwounds on the same bass.
Just my two cents.