What Boardpane can't do yet

Boardpane is version 0.1.6. This is the honest list — everything below was checked against the code and against a real Azure DevOps organisation, not guessed at. If something here is the one thing you need, say so at support@boardpane.com; that's how the next version gets decided.

What it shows

One organisation and one project at a time. Switching takes two clicks and costs nothing, but there is no combined view across projects.
Up to 100 work items matching your query. If you have more than that, you see the first 100, and the last row of the list says so and opens your work items in the browser.
Pull requests come in three sections. Needs my review and Created by me are fetched on their own, up to 100 each, so a busy project does not push them out. Everything else comes from the project's 100 newest active PRs, minus the ones already shown above, so in a busy project older PRs can be missing from it. A section cut at 100 ends with a row that says so and opens the repository's pull requests in the browser.
Nothing refreshes on its own. There is a Refresh button at the top of each view; Boardpane does not poll Azure DevOps in the background.
A PR counts as needing your review if you, or one of the first 10 teams in this project that you belong to, is a reviewer and you have not voted yet. Drafts and PRs you already voted on show under Everything else. Other groups added as reviewers (for example by a branch policy) do not count, and the team check needs your token to be allowed to read teams; without that, team PRs show under Everything else.

Work items

You can change the state, add a comment, create a branch for it (or copy its name), and (with Pro) create one.
You cannot edit a work item's title, description, assignee or any other field after it exists — use the Azure DevOps website for that.
No attachments, and no linking work items to each other.
A work item you create is not assigned to anyone unless your process assigns it, the same as the website's "New work item", so it does not show in My Work Items until someone assigns it. Boardpane tells you so when you create it.
The query behind "My Work Items" is a single WIQL query in settings. There is no list of saved queries, and your saved queries from the Azure DevOps website do not appear.

Reviewing a pull request (Pro)

Up to 500 changed files in one pull request.
Binary files are not shown. Images, PDFs and anything else that isn't text show "Binary file, not shown" in the diff. Open those in the browser to see them.
Comments are posted to the pull request as a whole, not attached to a line of code.
Complete always deletes the source branch. You pick the merge type (squash, merge commit, rebase, or semi-linear). If the author set up auto-complete, their merge message and "close linked work items" choice are kept; otherwise linked work items stay open. If you need the branch kept, or want a custom merge message or work-item transitions, complete it in the browser instead.
Complete turns down drafts and pull requests with merge conflicts and sends you to the browser. When a branch policy blocks the merge (a merge type it does not allow, missing approvals), Boardpane shows Azure DevOps' own reason; it cannot override a policy.
You can approve, reject, comment and complete. You cannot create a pull request, mark one as a draft, add reviewers, or resolve an existing comment thread.

Not in Boardpane at all

Boards and the card wall, sprints and backlogs, pipelines and builds, wikis, test plans, browsing repository files, and dashboards. Boardpane is a sidebar for the two things you touch all day — it does not replace the Azure DevOps website.

Signing in

In a folder you have not trusted, VS Code runs in Restricted Mode and the Boardpane icon does not appear at all. Trust the folder and it comes back — it isn't a failed install.
If your organisation blocks the one-click Microsoft sign-in, or it does not finish for your account, use Boardpane: Sign in with a Personal Access Token. The token needs Work Items (read & write), Code (read & write) and Project and Team (read); Boardpane checks it before keeping it.
Boardpane uses the Microsoft account VS Code remembers for it. To switch to another Microsoft account in VS Code 1.94 or later, open the Accounts menu, select your account, choose "Manage Trusted Extensions", click the gear next to Boardpane, choose "Account Preferences" and pick the account. On an older version, sign out of Microsoft in the Accounts menu and sign in again with the other account.
Only Azure DevOps Services (dev.azure.com). On-premises Azure DevOps Server / TFS is not supported.

Pro and being offline

Boardpane re-checks your licence key with Polar about once a day. If it can't reach Polar — you're offline, or Polar is down — Pro keeps working for 14 days. Past that, Pro features wait until the next successful check. Nothing else about Boardpane needs the internet beyond your own Azure DevOps.