I had a master electrician who I worked for use two tees under a kitchen sink rework to catch the dishwasher and RO system.
He used 2 sharkbite caps that held for 11 weeks so he was comfortable with the tees, didn't want to do any soldering for some reason.
I've used these a few times transitioning to CPVC only, not copper to copper. He said his wife was a better "leak detector" than any device, mirror/flashlight, or paper towel you can put under there....so....
Using them in last resort applications I feel is best. I would of preferred soldered connections rather than moving ones, was very hard to keep it all straight and from moving when installing the flexible risers.