Perhaps could be very handy to use with some specific meshes (for example to enhance glowing light) rather than the whole model?
Unfortunately, no, not in its current state. This is a "fake" bloom applied to the entire gP.hGL viewport including the background in the second render pass (stage 4 below) when the textured screen quad is rendered from video memory into the viewport with a distinct dedicated shader. In other words, the effect takes place in the entire 2D screen space after the scene has already been rendered. The vignette effect also has a similar dedicated shader of its own. The bloom shader makes all of the quad areas lit brighter than a given threshold appear yet brighter and super-sampled around the current fragment/texel (= screen pixel because the screen quad matches precisely the viewport's current size) to "leak" the bloom areas into their surroundings.
The current FBO rendering scenario consists of the following stages:
1. Render scene into MSAA FBO -> 2. Blit MSAA FBO into non-AA FBO's texture -> 3. Bind texture to quad -> 4. Render quad on screenA genuine bloom effect would require that stage 4 be split into additional sub-stages with yet more render targets/textures added for scene image minification, blurring, magnification, and additive blending with the original screen quad texture. This would complicate greatly the current OR dev stage. That's why I'm trying to avoid shader management over-complication till better times and tend to make a shift with as simple shaders as possible.
[P.S.] And no, you can't emulate bloom entirely with the straylight fader and/or light/material controls alone because bloom has a certain threshold below which it doesn't occur no matter what the current lighting environment is. That is, bloom is selective. Conversely, the brightness and lighting controls have a linear effect, i.e. they brighten and dim all the areas in all the materials simultaneously and proportionately regardless of whether they are bright or dark. And bloom intensity above the threshold level is exponential rather than linear.