Hi, I'm not a student in that course at KCL but for clearing, some schools do lower their entry requirements, while others do not. You probably already know KCL's requirements are "A-level (or equivalent) grade A in at least two of Biology, Chemistry, Computer Science, Mathematics, Physics or Psychology.", so if this is not what you have obtained in A-levels, I suggest you phone them and check whether this requirement still applies for clearing.
I don't think that phoning them would matter in terms of your application, as majority of the time calling up unis does not affect the application at all. So I would say call KCL, but not for the "showing of interest", but to know if the entry requirements are lowered or not.
I'm not particularly sure about the independent research as I do think that could be a good thing to have in your ps, especially with no biology or chemistry A levels. But, I think meeting the requirements is what is the most important for now, hence why I am suggesting you call KCL to clarify questions you may have about the clearing process.
Good luck on the remaining bit of the application process! 🍀