I suggest to look at my other effect construct.net/en/make-games/addons/1112/luminosity-mask-bloom it allows for much more control of your bloom
performant bloom that mimics a gaussian blur. It's supposed to be used with multiple passes.
bloomValue : how much the bloom should show up,
Threshold : at which brightness of the source pixels the bloom should be at max strength
lowThreshold: at which brightness of the source pixels there should be no bloom at all
To avoid artifacts use the following kernels depending on how strong the blur needs to be
2 pass = 0.5, 0.5
3 pass = 0.5, 1.5, 1.5
4 pass = 0.5, 1.5, 1.5, 2.5
5 pass = 0.5, 1.5, 2.5, 2.5, 3.5
7 pass = 0.5, 1.5, 2.5, 3.5, 4.5, 4.5, 5.5
(for example for the 4 pass blur you add KawaseBloom 4 times and the set the kernels for each effect in that order)
you can also try other sequences if you want larger blur with less samples for example 1.5, 2.5, 3.5 ,45. But you might get some artifacts (looking less like gaussian blur).
If you want to support me in developing more addons: ko-fi.com/fedecalchera