Customiser: Air cage for MK8 extruder with pipe end

Many fan shrouds for ventilation of the printed object exist, but none of those I looked at matched my needs: they'd not fit, feature a rigid nozzle without adjustment, block sight of nozzle and - more importantly - base layer, disallow intervention by means of a pair of tweezers or related, or are unnecessarily heavy and bulky.
In an attempt to learn from the problems with the solutions I looked at, I decided that air cage, surrounding and trapping air expelled from the cooler, and the nozzle