If they were to do something about this I would rather like they removed it from Boosts, at least favs, except perhaps 7 day shields or something else costly.
It was possible to get shield up pretty fast before they changed the Boost window - one only had to know the shortest route, and practice on it. 1.5 seconds was doable. One can still do this today.
As the game is now it is hard for low to medium players to attack as it is. Simply because, at least during competitions, there are always players that are much bigger then 9?% of the others. If you are at 3b influence and attack a town - and there is a 5-10 sec. "non shield window" you are going to take some serious hits. And pts wise it would likely be a disaster. In 15 sec you'd be zeroed.
It would result in a war game for top 4-6 players, in total, during CvC / KvK and a farmville game for the rest :P
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But, yes, I completely agree with you that it is an issue.