I am not quite sure that I understand.

What is a  bad mg?

Are you saying that your stronghold was upgraded to a level which is now inconvenient for you because its more difficult to win? That you now want to demolish buildings after you got the advantages of having them so you can get weaker opposition?

Are you asking that the chief can cancel the event after its started because its inconvenient for you personally.

I would have thought  that it is up to the chief to start the event when its most suitable for the majority of the clan membership.

Its a bit drastic but :

#1 you can(or could) demolish the present stronghold and rebuild with foreknowledge, but you never no what other changes may be coming, such that you need the one you have as it is now.

#2 Start a new clan and build again  as above.

RNG, not mg. Its randomly generated. Starting a new SH when all the sh knowledge and specials are about done is hell. 

Thanks .

Now its clearer what you meant.

As you not allowed to torch or remove some structures in town, or downgrade a building one level, which effectively has been asked for previously. I cant see them allowing this in the stronghold, and if they did allow it, how long would it take to implement it?

Being able to torch the necessary buildings would be the faster and cheaper option, but its possible that in the long term, or till you can cope with the higher siege level,if at all ever,a redo  might be the  rational thing to do, if you can no longer take best advantage of a siege now that your Tower of Odin has been upgraded beyond your current capabilities.

There's the option of not doing sieges for the time being.

I appreciate it's a question of the lesser of evils.

A question which may be helpful to others in the future.

Can you not stop upgrades in the stronghold after they are started ?

An option to prevent mistakes or sabotage might be useful.