Avoiding the dreaded Q plate on a scratch built chassis

Before I start accumulating parts left and right, I am trying to do my due diligence with regards to the registration process in the UK. I am trying to avoid a Q plate as by my understanding it can serious impact the resale of the car in the future, and it is legally very difficult to do anything about the registration (no personal plates etc)

With that in mind, what steps do I need to take to ensure I don't fall foul of the IVA?

I understand the rules say that a monocoque chassis has to be provided by a supplier (I have a gtforte flat pack chassis that I am improving upon) and that 2 major components have to be effectively unchanged but can be restored to new. Because of the nature of the transaxle, that's out which leaves me with engine and possibly steering (though uprights are included in that)

Am I overthinking it too soon or is it something I need to be mindful of before I even get the project off the ground?

I would love to hear from others who have already gone through the registration process

Many thanks