Sorry for taking a while to get back to you - I wasn't ignoring it!

There are no real consequences by not officially registering your tartan.

The only thing that could happen is that someone else registers your tartan - the colours and thread count etc. It would be a bit annoying if this happened I suspect.

You could obviously still wear the tartan, but it could be a tongue-twister or obviously unrelated to you. For instance Mr Tang Tai Zong registered it, the second question on peoples lips after asking what tartan it is would be to enquire if you're of Chinese decendancy Queue long story about how you created it first...

It is really up to the individual to decide if it means enough to them.

Over the last year, people registering tartans have mostly been from businesses - not for themselves.