They would be terrific on the Foundation 5. Another thing you should know is that they last for over 10 years and still sound great. The set I put on my last Gen 2 TL5 were on my Fender Roscoe Beck V for many years and I removed them when I sold the bass. They still sound and feel great.
I am a Thomastic Infield guy. I have three upright basses and two of them have TI Spirocores and the third has TI Belcantos on it. They make wonderful strings that last so very long. By the way, the last time I needed TI flats I called my salesman at
Sweetwater and got them cheaper than anywhere else that I have found.