Actually what you can do is use fine tuner and make the bomb 10 or 20 times the size having everything checked all four boxes. And then you can fine-tune it back down to normal size but leave only relative scale checked. So you get a big boom with a small bomb.
Unfortunately, the only way to change the explosion size of a bomb is the change the size of the bomb itself. If you want a large explosion, you need a large bomb.
Actually what you can do is use fine tuner and make the bomb 10 or 20 times the size having everything checked all four boxes. And then you can fine-tune it back down to normal size but leave only relative scale checked. So you get a big boom with a small bomb.
@Phoza ok, that makes sense
Unfortunately, the only way to change the explosion size of a bomb is the change the size of the bomb itself. If you want a large explosion, you need a large bomb.