Why are you doing so much extra unnecessary stuff if you're plan is to apply to Engineering, particularly at such institutions. Cambridge does not care about random language GCSEs, not does it care about an extra A-level in Electronics, and it barely cares about EPQs (only where relevant and even then it's just a bonus and by no means a requirement). What it does care about is having the strongest maths background, and a solid scientific background, which is a requirement and is the primary thing they will be assessing.
Taking it over two years won't affect your applications, although given your school teaches it in that format you may well find yourself "overburdened" in year 13 where you're doing more Further Maths than in this year and more "basic" maths. You may also find being further behind in maths than your compatriots makes it harder to keep up with the course.
Frankly you should be in the first instance looking to drop your unnecessary extra GCSEs, Electronics A-level, work experience, random competitions, your EPQ (project, I assume it's an EPQ) and relevant competitions (such as BMO or something) - in that order. The top universities for these courses don't care one jot how much of a well rounded egg you are, they care if you can do and more importantly learn advanced mathematics fluently and apply that to novel situations - which is primarily demonstrated by your core subject choices (and, potentially, BMO/similar, then EPQs on related topics).