Several years ago the 022 in my 1969 Vega quit running when I was cruising the Sacramento Delta. Two mechanics were unable to get it running. I installed an adjustable type bracket and used the 5 hp dinghy engine to get home. I was in a hurry and didn't add any reinforcing to the transom, just used a large fender washer on each of the four mounting bolts. I have been operating that way since.
The five hp engine will drive the Vega at almost six knots in calm water without a headwind, a lot slower in adverse conditions.
There are no stress cracks in the gelcoat around the bracket; such cracks would indicate flexing of the transom. However, I don't think I would want to rely on just fender washers if I had a heavier outboard.
Mort