What he said basically answers the question.
Reduce the cyclic gains by 2/3 from the standard 2-bladed head and that is a safe starting point.
Head speed can be reduced, but many (most) people leave them at the same 2-bladed headspeed - it makes the heli snappier and crisp in cyclic and collective.
I ran the 3-bladed head on my Trex 700N (retired), T600E Pro (still do), T600N (back to 2-blades) and Goblin 380.
I don't run a 3 blade head on my G700BN and I don't plan on trying it.
I used the same cyclic and collective maximum angles for setup.
Also, look for shorter blades. I experimented with standard and shorter blades. Sometimes the shorter blades were better, sometimes not so much.
The key to being happy with a 3-bladed head is to use the lightest blades you can find; otherwise, the cyclic response is noticeable worse.
On the T700N, I used the Align 690 3-blade pack and they were the best.
On the T600E Pro, I use the SAB 570 TB blades (there is no Align 3 pack for the 600) and then had to buy 3 2-packs before I could find three blades that matched. But, the 570TB are dogs but they are better than Zeal and any other blade between 550 and 600.
The T600N didn't have enough power to spin a 3-bladed head.
The G380 is a kick with 3 blades
If you run a high enough headspeed, blade weight is less a factor but your flight times are lower.
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