There’s a way to do this (in Windows), even if it’s not what we usually name a “keyboard shortcut”.
Reminder
In Windows, when menu entries are defined by the developer, inserting the “&” character before any letter in the menu entry, causes that letter to be underlined. The menu entry can then be activated when opening the menu while the Alt key is depressed, by hitting the underlined letter. However, you can configure the keyboard Accessibility settings of Windows to make the underlining of the prefixed characters permanent.
In Lightroom (english version) you can trigger this mechanism to open the Photo | Edit in menu (Alt | P | E). This opens the list of available external editors but unfortunately, the LR developers did it wrong once again : if you insert the “&” character in the menu entry text definition, it is ignored (the menu entry text is defined in the C:\Users<user>\AppData\Roaming\Adobe\Lightroom\External Editor Presets\xxxx.lrtemplate file corresponding to your plugin, by modifying the “Title” field). For example for the Nik Analog Efex plugin :
title = “Nik 6 Analog Efex”
The lrtemplate file is a text file that you can edit at will with Notepad or whatever text editor you are using. As mentioned above, adding a & anywhere in this text would do nothing. The “&” will just be displayed. Instead of following the standards, the LR developers are handling things very differently. Once you have used Alt | P | E to open the plugin list, you can launch a plugin by hitting the first letter of the plugin title (even if it’s not underlined). Since all Nik plugin names begin with a “N”, this is unworkable for these collection of plugins (same problem with other plugins). However, you can modify the menu entry by prefixing the title with a number :
title = “1-Nik 6 Analog Efex”
title = “2-Nik 6 Color Efex”
etc… (edit the titles before launching LR)
This way, for example, Alt | P | E | 1 will automatically launch Analog Efex. You can also use unique letters instead of numbers. You just have to make all titles first character unique.
Also, remember that the last plugin that you have used can always be relaunched with Ctrl+ Alt + E and automatically appears at the beginning of the list. It can also be launched with Alt | P | E | n. So, if you always use the same plugin, the shortcut is already available.
Unfortunately, the indispensable Keyboard Tamer plugin, can’t do anything about this very awkward programming practice. Too many things are hard coded in the LUA code of Lightroom (I’m still convinced that using LUA was a big design mistake which makes Lightroom incredibly difficult to debug).
Also, remember that using the Edit in menu is only mandatory when you need to export the image to a TIFF or JPEG file before sending it to the plugin. If your plugin accept RAW files, you can send the image directly to the plugin by using a simple script which will appear in the “Scripts” menu of LR. An LR plugin is merely an executable accepting a filepath on the command line. See this discussion for details :