Unfortunately, I know nothing about Futaba Tx's nor how their gyro menu's are setup. On a spektrum and JR Tx though they are as follows
DX6i, below 50% is rate mode, above 50% is HH mode.
DX7s/DX8, negative numbers are rate mode, positive numbers are HH mode.
On the DX6i, I suggest a starting number of about 65%. The 7s or 8 I suggest 35% positive.
You will just have to make this your own with your Futaba Tx. Wish I could help more.