Office 365 shared mailboxes are very useful. Unfortunately, they do not load outlook web add-ins right now: see http://stackoverflow.com/questions/35059067/make-outlook-add-ins-working-with-office-365-shared-mailboxes/35065215
This would be terrific to have add-ins for such mailboxes especially for all CRMs related apps

Would like to have an ItemSend event in the web API just like the regular API does. Is that on the planning stage for future releases?

Build out the specific host PowerPoint API with near complete parity to the control that was available in VSTO add-ins for PowerPoint. We have an add-in we want to build out in the new Web Add-in platform, but can't due to the extremely limited capabilities of the current Office.js API. You've had years to work on it, at least be more forth coming with where things are in development.

Currently, the requiredAttendees methods setAsync and getAsync have serious issues when resources of room type are used. I will add below my review of the three methods exposed on requiredAttendees object (picture in the link):

http://s17.postimg.org/satnvyrz3/Required_Attendees_Calls_Behavior.png

Currently, No Support to access Footnotes and Endnotes using JavaScript API. Please add support for search in foot notes and end notes.

Online Add in features need to be enhanced to have ability to resize Task Pane in Word online, Mac and IPad.

iPad also has limited resize ability and hence taskpane resize is needed

At the moment Word runs Add-ins in IE11

IE11 doesnt support ES2016, and is therefore much harder to develop for than all of the other newer browsers (Safari, Chrome, Edge).

Word should run Add-ins in Edge

The following list of events found on the client version of Word and Excel would aid in development of apps that work the same as current client addin apps work.

Excel Open Event
Excel Close Event
Excel BeforeClose Event
Workbook activate event

Word Open Event
Word Close Event
Word beforeClose event
Document activate event

Need a Change Tracking API in Word.

By default each procedure should only have the first procedure line (header) visible with an expand button to show all lines within the procedure. Currently a lot of time is spend scrolling through code.

I would also like to see the two drop downs for general and declarations changed to a tree view on the left so that I can more easily navigate procedures and methods.

Support wildcards for AppDomains in Office add-in manifests to support sub domains for example <AppDomain>https://*.acme.com</AppDomain>

Currently an add-in command will disable if multiple Outlook mail items are selected. It would be really useful to be able run certain commands by iterating over a collection of the selected items.

Create a angular component library for the office UI fabric. There is currently a library for Angular JS and React, but not for modern versions of Angular.

Please improve the dialog, it should allow to:
- set modality (right now the dialog is not modal!)
- have bidirectional communication, i.e. to have possibility to pass information directly from dialog to task pane and vice versa.

There are many use cases valid for both requirements:
- when you need to retrieve data from task pane (e.g. lazy loading)
- you have html where you fill the content, right now you need to pass them in URL which is not really nice solution.

Make it possible to use setSelectedDataAsync with data type “HTML” and “Office Open XML” in PowerPoint. Currently it is only Word that can use data type “HTML” and “Office Open XML”.

At present, if there are tracked deletions within a word, that word will not be found by search if either MatchWholeWord or Wildcards are turned on. This is a bug in search, but it is especially crucial to fix for add-ins.

There are several new features that are going to be released this year like Custom Functions or Dynamic Arrays which are extremely critical for our Addin and our customers. And those won't be available for retail version of Office 2016/2019

Microsoft should provide at least one time update for the Office 2019 to support these features so our customers can leverage the functionality ASAP without having to wait for next retail version!

For us it is critical thing as there are quite a lot customers preferring retail versions over Office365 subscription.

According to this...

https://docs.microsoft.com/en-gb/office/dev/add-ins/reference/manifest/extensionpoint#extension-points-for-outlook

...Addins are only supported for message read, on mobile. Can we please have a MobileMessageReadCommandSurface ExtensionPoint, so that we may create an addin for message compose, on mobile.