Harish Chouhan on "[Plugin: MailChimp for WordPress] Replace, add or leave as-is per grouping field instead of all-or-nothing"

Thanks for looking into this. I'll also provide a more detailed example.

Let's take two fields:
1. "Frequency", set to "Daily" by default
2. "Phase", set to "Interested" by default via a hidden field

I'd like people to be able to update the former but not the latter.

This could be a MailChimp for WP feature already, right? Just read the current field values for a subscriber and re-submit those instead of the forms default?

Instead of fiddling around with PHP/mc4wp_form_merge_vars or introduce extra parameters to take into account in our MailChimp setup, I'll wait for your update after you upgraded the plugin to support API 3.0.