Considering switching degree for postgrad is this wise?

What is the objective in doing an MA?

I may be doing the same thing, albeit for a second postgrad. It will be very hard I assume, but if you have an entire year to read up there shouldn't be too much of an issue. I'm not sure about the specific area though, as my knowledge of it is non-existent.

How was your first postgrad experience. And what is the appeal of a second postgrad for you, if you don't mind me asking? I'm just interested

I went from doing a psychology degree to a neuroscience masters.
The experience has been fair I suppose. To me it felt like an extension of the degree, but with more esoteric content and investigating things to which the answers are not yet fully understood - which I found really interesting.
I don't think too much more is expected of you, relative to how you would I suppose naturally develop academically... I suppose motivation is the biggest issue that I had (practically none much of the time! lol)

I did it part time (over 2 years) which I think added difficulty as worked alongside, who pushed to make me to as many hours as they could at times - so juggling was difficult (and if you do, I recommend no more than 15 hours if full time work or 20-25 hours part time).

As I feel that I have a good understanding of biological systems but not of cellular and molecular mechanisms, I felt it would be nice and interesting to learn more about it - guided by a taught program (or perhaps MSc or PgDip).

That's a pretty cool idea because a masters during long weeks on shift must be exhausting. Always pursue what interests you and what you want to learn about so good luck . Motivation can be a real ***** once you lose it and takes me weeks to recover.