dropdown list from the outside world

Hello,
excuse my bad english, I’m French (nobody’s perfect (;-) )

here is my problem.

1. I, as a service provider, design the form
2. my customer modify the wants to modify the dropdown content of the form using a csv or googlesheet or whatever spreadsheet, without having access to my form.
3. The customers of my customer, fill the form with the dropdowns tuned by my customer.

and everybody is happy using Typeform.

This feature would help a lot to give a new dimension at Typeform, it would be tunable withou acces to the form

I.E.

Imagin, I am a tour operator with many sales offices
I want to provide my sales offices with forms for reservation and sales of travels
I have a csv published with these datas:

my form using with dropdown can be be populated with these values ( I need to prepopulate the possible vallue of the dropdown, not the value itself)
today for destination my users will have the paris, London, Berlin choice
tomorow, if for example i add Tokyo, on my csv, my users will have Tokyoadded to theyr possible vallues of dropdown

I need something direct to customize dropdown without editing the form, this would open new usages to typeform

for information googleform has a free option called "form ranger" that do that
It is not fair for me to go to google form because may good typeform things are missing but right now i have no choice....

Please help me and do this to have many new customer (we all live in an open world, be part of it)
Thanks in advance

Philippe