Once you get into PEX ... your talking a lot of $$$ ... to me, the problem isn't worth an expensive solution.
If your a perfectionist, maybe ... but otherwise no way. The strips look great upside down and in the elements ... mounted onto cheapo $1.49 per 10' ... 1/2" conduit ... I'm sure in thinwall pvc might be a little better and cleaner ... but at some point you have to say 'good enough'. Its a personal choice of how sweet is sweet enough.
To me, all this fits into the same category with .... did you hang all your lights perfectly straight? Sure, it looks better ... but I also dont' have time or bandwidth to make em all perfectly straight.
Most people won't know the difference, so thats why its up to you to decide when you've done enough to satisfy your own standards.