Years ago i was riding my Gazelle titanium with headset spacers.
The Gazelle has a 1 1/8 inch headtube and i was using a 1 inch Syncros stem and a 1 inch Tange Switchblades fork.
The spacers were small, so you have to look twice to see the difference.
It worked very well.
I used all the 1inch stuff off my P7 on a Zaskar build usings some spacers called 'Shim Jims' many moons ago. All worked fine for years. The headset actually looks quite neat as the races are the same OD as the headtube.
I concur. Run my RC30s on my Dynatech using exactly the same system.
Only one thing - when time comes to remove the headset and ensure I leave the adaptors in the frame. Don't see that being possible and I can see a potential problem getting the headset out of the adapters. I hedged my bets and used a needle bearing headset so I wouldn't have to face this problem.