Firstname shortcode not picking up correct name in Theme Options > Email Setup

I am using the shortcode (firstname) amongst other shortcodes in one of my email layouts set up under Theme Options > Email Setup however when the email comes through to me (me being the admin) this field is picking up the username instead. My complete shortcodes are as below:

Username: (user_login)
First Name: (firstname)
Last Name: (lastname)

but, for example, for someone who registers with username johns and whose full name is billy smith my results in the email look like:

Username: johns
First Name: johns <— this should be ‘billy’
Last Name: smith

I asked support about this and apparently the latest update to the theme fixes this as it was a known error/bug so they recommended I download the latest version of the theme from my account which they say is 8 and install that. As I have made lots of custom changes to the code behind the scenes I am always weary of updating a theme just to fix a few bugs as it messes up a lot of what I’ve already done.

So firstly, when i download the latest version and look at the changelog (/framework/changelog.txt), that states the latest version is 7 (there is no mention of a version 8) and secondly where can I see a list of the updates/fixes that are available in the latest version of the theme as they seem to be hidden away somewhere?

Ultimately if I update this and functionality is lost, my client will need to be billed in order for me to fix it which they will not be happy with so I am reluctant to do anything until I can see written proof that the latest update (whether it is 7 or 8) will fix this issue. I had a feeling the support guys were telling me what I wanted to hear and as I responded to their last message then and never heard from them again despite leaving the chat open for a good 30 mins or so then obviously it doesn’t fill me with confidence.

If anyone can advise that would be great.

Incidentally is it normal for so many updates to be released on a theme? I rarely use WordPress because of the hassle it brings me (things like the above for example) but when I have in the past I don’t recall ever seeing anything other than 1 update of a theme. Maybe it’s normal and I’ve been lucky in the past, I just wondered.