If the business name is too similar to a Limited company name, and the limited company finds out you've registered it, they can apply to the CRO to restrict you from using the name (and will always win this).
This is still the case even if the two businesses are in seperate industries...
A limited company name is MUCH strong in terms of CRO protection.
The risk here is if your caught and you've spent money on your brand, advertising, on corporate identity - logo design, letterheads, stationary, printing costs, signage etc... that money will be down the tubes as you'll be forced to change it all and rebrand. That can be a significant cost...