I can understand Willy Messerschmidt's keeping the oleo legs on the fuselage for strength so the impact is taken by a strong section and not by the wings, how hard it would have been to alter the wing to change it to the config like the FW-190 is baffling given how good the Germans were at building things.
As far as the negative G getaway by the 109's to quickly counter this whilst the boffins got to work on the problem with the Spitfires carby cutting out the pilots devised a stop gap measure to get onto the tail of the 109 as it dove away.
And that was to roll the Spit onto its back pull hard on the stick and dive on the 109 inverted first then either rolling out or continuing the dive in the same attitude it became a nasty shock to some of the Luftwaffe pilots to find as they bunted to scoot away the Spit was still on their tail.
Cannot remember if it was in either a book by Tuck, Bader or Rob Doe I have but it is there and shoot the 109's down they did of course the new carby came out and that was that as well as up gunning the Spit with heavier 50 cals and 20mm or a mix of both.
From my library here is a little book every enthusiast should have do not let the size fool you its pretty packed with technical information on the Spitfire.