The Tizard Mission as a two-way technology exchange

How would the Second World War change if the Tizard Mission did not take place in 1940?

Both countries would lose technology exchange and joint work that helped fill gaps in their capabilities.

Without the 1940 Tizard Mission, Britain and the United States would lose a route for reciprocal technology sharing. American technology going to Britain matters alongside British technology going to the United States. Pooling their work is credited with helping both countries fill gaps in their capabilities, so removing the mission is expected to create serious wartime difficulties.