Ahh yes - I understand.
Some backstory:
Our SSO system, which now serves several external properties (including DevCentral), is still in transition away from using Email as UID. Historically, non SSO implementations found it easy to use email addresses as uniquely identifying a registrant. Many of our web sites were started, independently, many years ago (DevCentral will be 20 next year).
While we recognize email should NOT be a key field - until we can organize the migration for several of our sites togethr - it remains so.
So, that is why we can't let Community members change their email address (yet). We need to protect their account access for gated content on properties like Partner and Support from any innocent actions they may want to take for less-gated content such as you find in Community.
Now, Practically Speaking...and focusing on Community.
In your case - If you happen to change your corporate relationship with F5, where you may have a community account with community history (content, rank, etc) which you would like to maintain; in this case the DevCentral team can facilitate a change FROM your corporate linked email TO a linked personal email address on that same account. It will be easier for all of us to manage this if you can do that before you end your relationship with your company - but it is not mandatory.
What we still CANNOT do is accomodate a proper merge between 2 separate Accounts (e.g., pre-existing corp and personal) with different relationships to content from each.
By way of example, this means that IF you have already have a personal Community account AND a separate corporate community account we only have one, incomplete, option - to enable co-contributor for any CodeShare or Community Articles you may have written. This would enable PersonalAccount to maintain CorporateAccounts articles. Forum posts, however, must stay with the originating account. You could, of course, always comment on those posts to put them in your "notification" list. If there are a ton of them; that could get pretty arduous.
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That got long, my apologies; but I hope it's clear that this issue is important to me, and I am in touch with our SSO team to adjust some of this behavior. We have aims to increase your flexibility on community without risking the 'security' of your Partner, Support, or other necessarily gated accounts.
Increase Visibility on this Suggestion
One thing that would help elevate that conversation is a lot of Kudos, or further detail, alternate use-cases, etc on this suggestion. If you have friends on DevCentral with the same issues - have them kudo or comment on this Suggestion. I'll leave it open for a while as "Needs Info" - for that purpose and update ya'll here if/when things progress.