Che
ato wont overrun the tank if you just do some basic trimming. Thats the benefits you get with macro anyway, the ability to trim, remove and export the nutrients. Cheato is also a great matrix for pods to thrive an populate.
Ive had Caulerpas in my fuge with the Cheato. Both Grape and Red Grape. It was prety crazy in there for a while as all macro was competing for nutrients. In the end Cheato won, forcing the green Grape to start turning yellow (go sexual?). At that point I just removed all the yellow stuff and since then only a rare branch or two turned yellow on me. This is running 12 on 12 off photoperiods. EAch time i discovered yellow, nothing in my MT seemed affected. BTW, in that macro battle royale, I also had some Shaving Brush (not great for nutrient control but looks cool). After new "trunks" sprouted up on its own in different locations, it began to grow nicely until it degraded and started growing in another place again. Now the SB is barely hanging on with the Cheato and Red Grape almost completely consuming the canopy above.
The Rep Grape is still in there with my Cheato. There were times were I had to trim that stuff too. It never seemed to go sexual although when the Cheato expanded too close, a red hair type growth would accumulate on the Red Grape's branches. Even still I leave it in the fuge next to the Cheato as I have a theory it promotes competition in there and allows for more aggressive nutrient uptake. Its just a theory though. Red Grape does look nice though and really looks good as a Seahorse anchoring tree.
As far as Green Caulerpa, Ive seen a few successful Coral propagators use it amongst their corals in a frag tank. Helps with nitrate and phosphate control and when it gets too thick, its removed.. permanently exporting the nutrients.
I have Halimeda in a couple tanks. I love it, some people dont care for because of their Ca needs. I think it adds a nice vibrant touch of green and nothing in the tank eats it. But instead of nutrient control, you get Ca usage. Defienelty a cool plant, have a couple sprouts popping out of the sand in remote locations, as well as the Mother plant which got its holdfasts firmly anchored to a large rock.
So thats basically my year long experience on macros nmimummi

hope it helps.
BTW a mix of Miracle Muds were used as a substrate in my refugium, MT is BB. The mud I beleive, contributed in at least some capacity to my results.