23' I/O swim platform mounting ?

[abl1111]

I am planning on installing a teak swim platform on the 'ole 23'Tsunami i/o this Spring. It is about 6 1/2'-7' long and fairly lightweight ( always a scupper concern !!!).

I will be using (4) AFI SS, 3-sided mounting brackets to mount it.

A few questions for those who have been there... done that:

How do you calculate where the bracket should be mounted w/ relation to the waterline ? I want the platform as low as it can be mounted without hitting the drive when fully trimmed and so when taking off and underway, the platform will not inhibit performance (i.e. be under water )

To avoid transom water damage, has anyone done the 'drill larger holes, fill w/ epoxy and then re-drill smaller holes for the thru bolts '?

Lastly, being that I have a Bravo 3 ( SS props ), will the add'l SS brackets underwater create more noticeable galvanic corrosion ?

Thx