Except the first 2 are examples of human error. You are supposed to follow the instructions, and the instructions tell you to carefully read the instructions which I have done with multiple 'manual' antigen tests. They're crystal clear. With regards to these 2 examples you can ensure decent lighting with a smartphone (torch) these days. Incorrect timing, can also be solved with a smartphone by setting an alarm (or just focusing on say letting 15 minutes pass as a matter of respect to the outcome and those possibly affected by it). We already got a swiss army knife in the form of a smartphone, we don't need another disposable technology (nevermind insecure technology).
While I was doing my test I read instructions carefully but then after few minutes of gathering courage to stab myself (surprisingly hard to do) in the finger I managed to mess the rest of the procedure up by putting buffer fluid, or blood, I don't remember, in the wrong hole.
