Sorry for the misunderstanding. If I understand correctly, you are searching for a solution that would automatically invest transfered money into a given strategy and allows for quick changes in the strategy toward cash?
I’d simplify the currencies, convert them through a cheap service like Revolut or Wise then use a cheap broker, like InteractiveBrokers, and buy a single widely diversified fund (or just a few if you really want to add commodities).
JustETF has a pitch on the ACWI index that I find convincing: https://www.justetf.com/uk/academy/how-to-get-a-globally-diversified-portfolio-with-just-one-etf.html
If you want the buying to be done automatically, I guess that takes us in robo advisory territory. I am in no way knowledgeable in that field so take anything I write with a grain of salt. @investinghero has a blog post comparing their services: Switzerland’s Best Robo-Advisors - Comparison
You could also use services by other brokers. I understand some German banks offer it: Why are there no ETF Sparplans (ETF savings plans) in Switzerland?
Others have more experience and are way more knowledgeable than I am in those fields.
As a side note and for 3a assets, Frankly. invests new funds and allows for the selling of stocks (going all cash) on a 3 days basis for index solutions and 2 days for the active ones. One can theoretically change strategy in 4-6 days (I haven’t tried it: 2-3 for selling assets in an active/passive solution, then 2-3 to buy them again).