FTSE global all cap index

Hi guys. I have been investing in the S&P for a while now but I want global exposure as emerging economies like China and India etc are on the up, so I want to diversify my exposure to world wide.

But 67% of the global ftse all cap is still weighted towards America.

I want this to be a set and forget so I can DCA every month until I retire. Will the FTSE global all cap rediversify and shift its investments to other countries more if other countries become a lot stronger economically so it’s less weighted to the US, or will it always stay within these weightings? I am just very conscious my portfolio is incredibly weighted towards the US and I would like to diversify more, so just wondering if the ftse world fund would do this automatically so I can truly set and forget it.

I won’t be retiring for another 30 years and I don’t think the US will be the leading economy in the world over the next couple of decades which is why I’m asking - I don’t just want to invest in the S&P solely now and not have any diversification outside of the US?

Another point is, because I am a UK investor the pound is gradually getting stronger..

My main concern with the S&P now is the pound getting stronger to the dollar which naturally offsets gains on a S&P tracker. Will all the geopolitical stuff and things gradually moving from Chinese Yen to USD doesnt bell foreign investors because if/when the dollar gets weaker that also effects the value of mg investments