BG Blur slider blurs the LightWrap matte as too

This will get rid of the to detailed matte for the light wrap and lets
you adjust the light wrap detail as needed, both on the BG clip itself
and the matte…

Just switch to Matte View and select the LightWrap for the matte output
and ajsut the BG Blur slider, Gain and Threshold to get an idea what
you adjust with those sliders…

enjoy