IMessageEditorTab check Tool

I'm trying to create a simple jython extension to run a regex against the HTTP response and extract key fields into a new IMessageEditorTab. Is there anyway in IMessageEditorTab.isEnabled or IMessageEditorTabFactory.createNewInstance to check which Tool you're in? I only want the tab created in Repeater (and ideally with a different regex per tab). On a big project it's killing burp :( In IContextMenuFactory.createMenuItems I can get the current Tool from IContextMenuInvocation.getToolFlag(). Thanks