It WOULD be a good target IF...
If the water model for these recent flows is correct, then clearly they are a target for landers.
If a gas/ice model is correct, then clearly they are not.
So it's important to understand the ice vs water issue before sending a lander on a potential fool's errand.
I personally favour the Sisyphi Cavi region of Mars where we see regular springtime flows, every Mars year. A mission here would answer the question of water involvement quite easily, and with appropriate timing and equipment should enable the direct observation of active flows.