I used the 2018 Crazy Light Boost basketball shoes for tennis for a few months.
For context, I am a 4.0 player in my early 40's, and when I play with people in my age group or older, I have been called "speedy," and against younger guys I am "normal" lol. I do not consider myself an "aggressive" mover, but I do run after most balls and I also try to serve and volley as much as possible.
With that said, the Crazy Light Boost cushioning was hands down the most comfortable, but it did take a little bit of getting used to with the "pillowy" feel that is more plush and a little higher off the ground compared to shoes like the Barricade Boost or the first gen Court FF. I also felt a little awkward on the side-to-side movement at first, but it wasn't an issue after the first couple weeks or so. The outsole also are not as sturdy as tennis shoes, but for me they held well for 3-4 months of singles play. I definitely could see these wearing out fast if a younger, aggressive moving player were to use them.
I think I could have gone at least another month with the CLB, but I use them now for walking my dogs or casual hikes at nearby parks. Ultimately I went back to using the recently discontinued Barricades with custom fit insoles. The insoles do a great job overall for cushioning and arch support, and the Barricades have great stability and last forever so it seemed like a good combination to me. Once these wear out I will probably try the new Court FF.
I think it might be worth it to go to a nearby mall to try out some basketball shoes and move around in them to get a feel for how different they are compared to tennis shoes. None of the retail stores I went to had the CLB, but they will probably have the latest versions of Hardens or Lebrons, which will give you a general idea. It is definitely a niche choice for shoes for tennis and it definitely feels different, but if you like the cushioning and comfort, and you feel like you can get used to the different feel, it might be worth taking the dive. But I think it is certainly understandable if anyone feels that the cost is not worth "experimenting" with shoes, since there are great tennis shoe options as well.
Will provide pictures comparing the CLB to my barricades when I get home!