I tried some ways but I'm not allowed from our DNS panel to import the configuration WITHOUT transferring the ownership to Wikimedia CH. We have a ticket opened to fix this problem, since we don't want downtimes.

(The upstream ticket in WMCH is still opened. We need to wait.)

Please note that the screenshoot is outdated :-)
Technically, this isn't even needed. The DNS zone can still be hosted in infomaniak.

This is declined :) not because WMCH does not want it; but for the exact contrary reason:

This is declined because WMCH asked to import everything in WMCH (to manage DNS with WMCH's name servers) but I see more downsides than benefits in doing this. The most prominent benefit would be: WMCH being more independent in updating DNS records (but without many proofs, since, at the moment, I'm authorized to manage the DNS area of dicoado.org, and, Lorangeo is very fast in updating their DNS area as well as far as I can see).

Downside of importing everything in WMCH: we really have no collaboration tools for the DNS area, so, community owners would be excluded from this management (as far as I can see).

Since I know that both Vivian and Lorangeo has sufficient IT expertise to manage their DNS zones, therefore I'm inclined to preserve this balanced situation, at least at the moment, since we have more downsides than benefits.