DeBaat has been moving. He lives in the Netherlands and I believe has another job besides doing the WP plugins or add-ons so there is a bit of a lag. Extended Data Manager is a third party add-on by DeBaat. He has been notified that he needs to update his code to work with latest versions of SLP.
DeBaat has his own forum Third Party add-ons. For EDM please post in that forum.
As far as Power add-on. We have not received any info regarding that it is not working.
You mentioned you had ProPack before. The latest version of ProPack has been working with version 4.7.4 of SLP. The Power add-on works better and more efficiently but also added other functionality that was in Tagalong, Pages and Contact extender, so it was actually 4 plugins that were replaced with Power.
The process was announced in July 2016 to manually update from your account. ProPack version is now up to 4.6.5 please check the documentation site, i.e steps to take. We cannot guarantee it will work with Future SLP updates. It is a legacy add-on. Regular news feeds are posted with changelogs. Please follow the news page, or follow us on Twitter, Facebook or Googleplus for important update information.
When posting in the forums please provide your plugin environment and your site URL. I see that you have also been emailing support. Asking questions in the forum is preferable then a back and forth exchange via email, especially if there are any errors to report. The forums helps everyone and is more efficient
Could you provide the required info per the posting guidelines.