A quick look around Wordpress.com's website suggests that they have no public bug tracker. I think the only way to get the attention of their engineering staff would be for a WMF employee with access to the Wordpress account to contact their support, since even that is only open to paid account holders (I'm assuming here that the "Wordpress VIP" mentioned earlier is one of their paid services).

There is currently an open bug (T50373) for merging $wgAccountCreationThrottle into $wgRateLimits. If this is done I assume it would be possible to modify the rate limits configuration to remove (or set to a level that account creators would be unlikely to hit) the limit for account creators.

This looks easy enough to implement, although once this is done another bug will need to be filed to modify the accountcreator group on enwiki to use it instead.