Interesting that you went for the "Lectra" both our's and Chris' are Lenco so time will tell how you get on! Agreed the switch looks nicer!
Re strengthening, it does just provide a little piece of mind knowing how strong they are. I have even found them useful for climbing up into the boat (not regularly, just when necessary) and it makes the transom access route much easier I think. With these physically large sized engines, the cowling extends out so far either side that climbing up the skeg is hard I find.
Top speed will not increase I don't think. I know Channel Ribs is an opponent of tabs on ribs but we find that they are very very useful. The conclusion of our trials last year resulted in us deciding the engine is slightly too high to be perfect for us but nothing proper trimming can't solve as demonstrated by CR!
I think the most telling thing was on the way back from MtStM last year, we were able to comfortably run at least 5 knots faster than La Frette which I don't think on its own the extra half metre could achieve nor the extra crew of LF. She was certainly bouncing around a lot more in the head on 1.5ft? chop, which for us was not too bad at all.
So when do we get our consultation fees?