It is expandable. You can for example you put splitters in and make a second loop. (Or enlargen the existing one.)

It does work of course. Though I personally don't see the big advantage of it. There have several times been threads about this and in the end it always comes down to personal taste.

In the "general discussion" thread there is a 5X8 one. (You really shouldn't post the same thing twice)

But in your solution each input direction has a section with only 2 belt width. So if one of those inputs is more than 50% full it will bottleneck and a 75%-25% ratio will neverproduce a filled belt.

But you can research with the max speed until you run dry. If you are researching something that would be beneficial RIGHT NOW and you have enough science on the belt you get it a bit earlier, which can be an advantage. For example another quickbar, additional inventory slots or better electric ...

5X9 here, saving you 3 tiles. Or a variation (same size)
Edit:
Found 6X7 one (and it's the easiest of all of these)