
How about some half the size – 50 thou or 1.27mm?
That is just what Mac8 of Japan makes.
You combine its space-saving HHP 1.27mm pitch surface-mount board edge connector – two or three-way – with its minimalist (U-shaped piece of wire*) JHP-3 jumper.
The HHP-2 (diag) is 3 x 3mm, the photo is of HHP-3s.
There is a data sheet, which includes the sort of note that some company’s forget: As the crimping strength between the contact part and the resin part is weak, please apply an adhesive to the both sides (PC board and resin) and use.
*phosphor bronze, and looks like they found a way to round the ends to prevent snagging – neat.
The photo of the jumpers in action is taken from this Rohm eval kit user guide, mentioned in this article.