Thanks for this. As this is the single feature that I miss most, and is preventing me using DEVONagent as my default browser, can I make a plea for this to be included in a hopefully near future update? In this regrettable age of cyber attacks and general web insecurity, and advancing age with increasing difficulty remembering passwords 
using a password manager is becoming essential!
I keep 1Password mini running (set in 1Passwordâs preferences), use the default Command-/ shortcut to activate it, and then search/copy/paste from mini into DEVONagent. Itâs not as quick as using the 1Password extension in Safari, but it does work well.
Simple when you know how! Thanks or porting this, I have now implemented this and it works well. 
In the grand scheme of things, it could make sense to rethink DevonAgent as a browser extension. Safari is probably too restrictive for this, but on Chrome and/or Firefox it should be feasible, and it would allow DevonAgent to partake of other browser features and extensions.
LastPass bookmarklets are now deprecated. Any workarounds known to the community? thx
Your brain? 
not as nearly as reliable as DevonThink ⊠
Hahaha! Touché 