So at UCL admissions have two sides, the departmental side and the central side. Ultimately decisions are made by central admissions, although the department can provide context/information or advocate for a strong applicant. At least, this is how it was explained to me by my (then future) department.
What this means is that they will see you applied to 5 different courses at UCL, as at some point there will be a central admissions person looking at everything. I can't say for certain whether this would impact your chances of admission but realistically, in the UK there is a great emphasis on focus on the specific course being applied to, rather than applying "at large" to a university or having a more vague idea of the academic direction you're interested in.
Therefore I think it's at the least unlikely to be a positive effect and at best will be net neutral, and I think there is a reasonable chance it would reflect poorly.
I'd just suggest picking the singular course at UCL you are most interested in and applying to that one, and tailoring your PS and application around that. You don't have to use all your choices if you don't want to - I only applied to one course at UCL because I knew it was the only course available at UK universities that I wanted to do which I was able to (due to constraints on my with respect to study mode and commuting).