There is no way for an add-on tool to do what you are asking. You might try making a topic in the Suggestions forum. You also might try using BOB, which has an option to display pop-up dialog boxes asking if you are sure you want to deploy, to end assaults, to end reinforcments, or to make the one reinforcement you are allowed in anything other than an unlimited reinforcement game.
Okay, can someone move topic to Suggestions forum or do I start a new topic over there.
I understand the option of pop-up displays in BOB. Just seems more troublesome. Let's say that on a 100 rounds I play, it only happens 1 time that I want to go back to assault mode. Using BOB pop-ups I'd have to click 100 times to get further to reinforcement but only 1 time it would actually be useful.
Thus it would be much more userfriendly to have this button that you only have to click in that 1 situation where you want to go back to assault mode.
It might be better if you started a new post there, as they have a standard form for the first post. You might want to search to see if this has already been suggested, as it seems somehow familiar. Be warned: I guarantee within the first 15 posts (probably less), someone will intimate that if you are too stupid to think before you end assaults, you should't play.