Floor insulation gaps between ventilation pipes and empty conduits

Hello,

I am now about to install the additional insulation. That is, the insulation under the underfloor heating.
Below are 2 example pictures from the upper floor. What is the best way to fill the gaps/cavities?



On the ground floor, I don't have ventilation pipes, but empty conduits also cross there.

bituminous insulation filling e.g.