I think you are on the right track .... I have extensive experience with the Wimberly flash bracket that attaches to their gimbal AND the better beamer.

Raising it and having it forward of the camera improves it's function

Most of the time I use it for "fill flash" with the flash unit set to manual at a reduced power level such as 1/64 power. The effect is subtle but can be helpful in providing enough light to increase shutter speed a bit and enhancing feather detail

I have also successfully employed ETTL settings but usually at reduced power such as in the range of -2 to -3 stops.

I have had birds spook from the pre-flash but not all that often.

You will need to experiment a little each outing by taking some shots and looking at the histogram but it is a very useful tool IMHO.

In most cases I don't like the look of images with flash at full power.

PS: make sure your flash is set to the correct "zoom" setting recommended by "beamer" manufacturer.