I have been reading about building various aircraft, and some of the modifications that are done to them. I am leaning toward an all-metal build, but some research has resulted in some interesting thoughts. The 3 things that really made me think were: 1)A CX-4 where the wing ribs were redesigned to be CNC cut but used bent tab fasteners rather than the dimpled rim design. 2)Reading about the KR2 design and safety record. Basically (as I understand), almost no one built a stock KR2, and that makes some unsafe, but those modifications resulted in the KR2S, which has a much better safety record. 3)A Trent Palmer video where he added a leading-edge cuff to his wing and, after testing, found that it increased his stall speed rather than decreasing it (as he intended). While these things seem only marginally related, for me they underscored how modifications can make an existing design better fit your mission, but can also have unintended consequences. I am looking to understand how to avoid the latter.