Some letters appears to vary kerning width depending on data values

[deepspacemillar]

Hey folks - firstly, this is a really cool idea and I love the implementation!

I have found a spacing issue when playing around in a sandbox - the letter 'A' (maybe others too) varies in width beside certain other letters and depending on the values being used.
This is the wider variation

This is the narrower one

This means very obvious movement of letters on dynamic data
I have a basic test case here;
http://elementstudio.co.uk/Datalagreya%20test/spacing-issues.html