I suppose some of my posts may appear negative its genuinely not the intention. Certainly from my point of view I have been lucky in having good people around me to advise me and wanted to try and help stop what in my opinion, and it is only one opinion, may turn out to be things you will later change and incur expense in doing so. I try to do thing right the first time as the money invested in these cars is never recovered and the cost of changes soon add up. Specing a car for a season of hills and sprints only to find rule changes mean expense in adapting to fit rules is bad enough but having to redo something you have paid to have done is not a good scenario.
As an analogy if you were building a house and had sub contracted the building work to a builder and decided to project manage it yourself. Would you simply give the builder the plans on day one and say, build me that and walk away until it was built. Live in the house and then discover, i don't like this or that and have to redo it.