Ive been using this for some time and now have to adapt (as you have) due to changes to the way Firefox changed the way addons worked.
Thanks for continuing with this addon - it is really good.
However, I have a couple of issues.
1. I have a web application that provides (linked) IP addresses (as well as hostnames) - that is you can click on the IP address to drill down in the native application. Before the latest ipprotocols (1.2), I was able to hover over the IP address, obtain a pop-up window and move the mouse and select SSH, and be taken directly to the device - this worked well. Now, in the latest version, I do not get popup window. In order to get the SSH, I have to click on the IP address - but because it is an active, linked IP address, this doesn't work and continues to drill down the native application. Can the popup be re-instated?
2. There doesn't appear to be an obvious way of passing the username to the SSH session - unless I am missing something.
To get around the issue, I added the following to the .bat file.
setlocal enabledelayedexpansion
and modified the following SSH part to;
Start "SSH" %SSH_COMMAND% -ssh %USERNAME%@%ip%

Since the USERNAME was in the environment for each users login, this successfully passes the username to the SSH session, avoiding the user re-entering their user name.
Does have a security benefit of not being able to use a different username - although others in OPs may see this differently.
So number 2 may be taken as a tip/idea for others wanting to do the same.
Havent found any issues whislt doing this.

3. When having more than 1 option selected, e.g SSH + Ping + RDP, only the 1st selection has a (white) background. The remainder are transparent, meaning it is not possible to see the option text easily.
How can I put a background around the entire selection by default. I do notice that some static websites that I use do not have this issue so it could well be that this is related to the specific application.

Great product though and has really helped my work.