Do you mean Arrow Ti rods specifically, or just Ti rods for Commandos? I bought a pair of Crower Ti rods for a Commando around 20 years ago. It turned out that the small end weight of the rod was only a little less that a steel Carrillo rod, so I didn't see much benefit in it. I think they cost me $600 for the pair. Today, you can get a more modern design Ti rod, and I'm guessing that the small end weight would be significantly less than for a comparable strength steel rod. If you can't reduce the reciprocating weight, what's the point of paying for a Ti rod. The Arrow design looks like it should be significantly less than a similar steel rod, so might be worth it. Carrillo will make Ti rods to order, but they are pricey. As I recall, the last time I talked to them about it, which was probably at least 10 years ago, the dealer cost was about $600 each, and they wanted a minimum order of 8. I'm sure it would be much more painful now.
Ken