The spatial evolution of young massive clusters

[Context.] Gaia is limited in the optical down to G~21 mag so it essential understand biases introduced by a magnitude-limited sample on spatial distribution studies. [Aims.] We ascertain how incompleteness observations of young clusters affects local analysis tool INDICATE and subsequently perceived properties these clusters. [Methods.] created mock cluster catalogue from synthetic dataset using observation generating MYOSOTIS. The effect distance, uniform variable extinction, binary fraction, population masking point spread function wings high-mass members, contrast sensitivity limits trends identified are explored. A comparison typical index values derived for members their corresponding made identify any significant changes. [Results.] typically find only small variations pre- post-observation populations, which can increase as percentage binarity. No strengthening, or false signatures, stellar concentrations found but real signatures may be diluted. Conclusions drawn about behaviour Gaia-observed populations that are, not, associated with natal nebulosity reliable most behaviours individual change should used measure between intrinsic (e.g. mass, age, object type), rather than draw conclusions specific observed member. [Conclusions.] robust reliably study within 1 kpc, up 83.3% binarity 50%.