OK, I see. I'm pretty sure you will not be disappointed with the Kode 74 compared to the Acid 73. It has a slightly different feel to it, but overall I think it is just plain better. Even more compact and turny, amazing stability on the rail and more snappy off the top than earlier Acids too.
But as you say, you will still have to live with two different characters if you go with the small Kode. There are good and bad things about that. One one hand you will not be as in tune with the boards and always have to slightly adjust when changing. But on the other hand I think riding different boards open up for learning to approach the wave in different ways. You might get a bit stuck when only sailing one style.
And with the Kode 74 and Quad 81 (or 76) you will in practice have a lot of overlap. At your weight the 81 will easily handle 4.7 and in some conditions 4.3. And the Kode 74 will easily handle 4.7 and work with powered up 5.3 even at your weight. So there will be many days when you can change between them and simply learn to change which mean the transition will eventually be automatic.
But if you end up liking the Quad 71 that will maybe be best overall. I hope you'll find an opportunity to try. If you happen to do some sailing in south/west Sweden, drop me a line With some (a lot) of luck we may be able to team up. Unfortunately I don't have a Klitmöller trip planned for this year.