Before I switched to these flats, I played a custom set of Rotosound Swingbass 45-60-80-105 that I assembled from singles through the Rotosound rep & JustStrings.com. You can hear what they sound like on the Lawrence Welk Special "Precious Memories" that occasionally plays on PBS fundraising week, or purchase a copy through the Welk Theatre in Branson, MO. The 9050CL flats have marginally more tension than the same nominal gauge of Roto Swingbass, since there is more mass for the given diameter since there are no gaps between the windings as with rounds.
On my Rickenbacker 4002 I still have rounds: GHS Progressives, again as a custom set assembled from singles of 45-60-80-105; before I hurt my hand that used to be my main gigging bass, and I've played that setup for almost 20 years. On the CCB I recently got, I have Thomastik Spirocore S42 Weich on the EAD and a different G string, which is not uncommon. My Miraphone tuba, of course, doesn't have strings.
When I used to gig more, and changed strings more often, I would experiment occasionally, always going back to this setup until I got the 9050CL's on my custom P-style fanned fret bass.
Here's the deal as far as tension goes. Since the strings have a similar alloy, whether chrome or plain steel, they will have about the same density. So you can use the D'Addario tension chart to get a ballpark idea of how much tension the strings have. It won't be exact, but it will be within a few pounds. Moreover, you can compare how the different formulations, nickel plated rounds, stainless rounds, and flats, compare tension-wise. I would venture to guess that compared to the set you play now, which is probably 45-65-85-105, that the 9050CL 45 flat G string and 105 E string might feel a tad stronger, and the 60 flat D string and 80 flat A string will feel very similar to a 65 wound and 85 wound, respectively, tension-wise.
I finally got around to taking a picture of my custom P-style fanned fret bass, attached.