So how should it work? Because disabling the quake means an easy way to abuse it

I think when you disable quakes, it should reset the progress on making a quake.(less logic, but prevents abusing), if you mean this.

Other ways are stopping the progress or gradually reduce it.

This can be easily abused by enabling the quake 5-10 seconds before you need it - in other words, it does not fix the issue. Any other ideas?

No, I won't add this feature. Blast affects neighboring towers and now you have to deal with it - you are playing a strategy game and challenges are a part of its genre.

Build it apart from other towers or surround it with modifiers. It is not a bug and is not something gamebreaking - it is a challenge and I like it.