Well I installed my bracket myself. I filled the hole!!
I would not like it the way yours is!!
Although it is probley fine. If the transom is solid then it should be fine.
On the safety side of things, if that, seal around the bracket failed, deck cover leaks, or the plug on the bottom of the bracket fell out (unlikely) and the bracket started to leak, It would just keep filling the boat!!
I noticed that after the first year of my install I had to tighten the bracket up some. The bracket had squeezed the transom tight and cause a small 1/16 or less space in a small spot. I was concerned about a small leak getting into the transom so I added some more 5200 and re tightened the bolts, Has been fine ever since.
And if you are moored and don't go to the boat for a few days, you just might find it on the bottom!!
If were me I would plug the hole from the inside!!! Should not be to hard for you to do your self.
Here is mine inside, after I re did the hole!!:
Outside work in progress:
