Valve placement / safety concerns

Hey. I'm installing an RO system, and because of the way the cold water line is set up, I couldn't place the needle valve where it's intended (where the shutoff valve is). So what I did was buy a short 3/8" m-f extension and plug it into the shut-off valve, then install the needle valve where the extension meets the original riser tube. It's hard to tell in the images, but the shutoff valve is there, it's just a screw that doesn't have the cap on.

Does this seem ok? If the needle valve happens to be closed, will water coming through have issues because of being briefly diverted into the extension tube?

Could I have solved this in a much better way to begin with?

Before/after (tubes not attached yet) pictures are attached. The needle valve that I installed at the bottom of the "after" picture.

Thank you!

Not fond of needle valves but if it doesn't leak that should be okay.
Not sure what you meant about being okay because the water is diverted through the extension tube.

I have never seen a valve like that in the wall. is the white thing that looks like a golf ball tee a tool to open and close the valve in the wall

Mr_David said:

I have never seen a valve like that in the wall. is the white thing that looks like a golf ball tee a tool to open and close the valve in the wall

Click to expand...

Yes, it normally has a white plate that it sticks out of, which hides everything behind it (for aesthetic reasons?). It's a push/pull flow stopper.