Hello,
Delete a domain name is bad for SEO.
For example I want to change domain name but I pay 1600 credits + 500 credits for service :
If domain name : www.example1.com expires then forumotion will reserve the new domain name www.example2.net for me and I choose the new domain name in administration panel to cherish a max from 2 domain names.

I am sorry, but I do understand what you are asking.  All forums have a default link.  Domain names are an optional feature that you can purchase with credits.  Domain names are only good for a year, but you can renew domain names.

Hello,
I can delete domain name anytime to retreive default domain name.
Some people delete his purchased domain name to buy a new domain name.
We want to automate this process then you can also change domain name for 2100 credits.
You fill in informations of new domain name and forumotion team will do rest of work : book the new domain name and change forum redirection from old domain name to new one.

Hello,

So is this not a problem. It's a suggestion, and you can ask for this here https://help.forumotion.com/f29-suggestions
Also I can see on your profile that you are speaking French, if you are more at ease with language know that we have a support forum in French, right here : http://forum.forumactif.com/