For strong turbo road engine I would concur

You're not looking for the last .001% VE so a robust 1 angle job would IMHO probably be better than a 3 angle
Well that's according to conventional wisdom at least

I have also been following a developing school of thought too

Their argument is that a 3 angle might actually be more heat resistant. The argument goes like this:-
with a single angle you typically cut say 60deg. This gives you a little bit of a knife edge effect where the head material is a little bit thin around the throat entry. This makes it prone to overheat in extreme conditions.
If you go for a 2 or three angle job you can increase the throat cut to a higher number, say 75-80deg. This gives you less of a knife edge and hence more heat resistance

I can see the logic in this argument and it has me confuddled TBH

Whilst I can see the advantage of this you get the disadvantage that a multi-angle job is much harder to lap in leaving you with a tendancy to local hotspots due to different valve/head contact
But then with a single cut you get reduced chance of valve burn as it can generally be lapped in a bit better but you slightly increase the risk of head burn with the knife edge throat

Out of all this I have concluded that were I to do a head myself I would go single angle. Given limited tools (and talent LOL) I have more change of producing a well lapped and sealed single angle head than multi

Then again, what about a 2 angle. best (and worst) of both worlds

My tuppence on the subject. Kerplink!

Hope that has helped and made the answer crystal clear for you LOL