I'll plug this here again now that I can share it in a useful way:
If you make a bookmark to the below URL (using whatever instructions are appropriate for your browser of choice):
javascript:(function()%7Bwindow.location.href %3D %60designer%3A%2F%2F%24%7Bwindow.location.hostname%7D%3A%24%7Bwindow.location.port%7D%3F%24%7Bwindow.location.protocol !%3D%3D 'https%3A' %3F 'insecure%3Dtrue' %3A ''%7D%60%3B%7D)()%3B
Which is essentially just the URL encoded version of this code:
function() {
window.location.href = `designer://${window.location.hostname}:${window.location.port}?${window.location.protocol !== 'https:' ? 'insecure=true' : ''}`;
};
You can navigate to a gateway webpage hosted anywhere, click the bookmark in your web browser, and it'll invoke a deep link to that gateway, even for 8.1 gateways.
Instant productivity boon if you're frequently working with different systems, including 8.1.
Disclaimer: As you can see in the code it's deliberately opting in to allow plaintext HTTP launching, which deeplinks are designed to discourage. I consider this a totally acceptable thing to do in development environments, but your company/IT department/grandma may not.