I’m confused. Didn’t the select person dialog already have such a find/filter until a threshold is hit? (Like about 1,000 people?) My tree has long exceeded that threshold. But I recall grumbling about the search becoming disabled.
And also, the experimental recent-items addon by @kku for the select objects is a huge accelerator for data-entry. I would prefer its use of row space.
Also, after discussion the recent‐items implementation as an addon was deemed to be preferable to being rolled into core.
Could this be similarly made an addon? That could allow customization of the Selection Helper modality.