First, I am very glad to have come across your fonts and I like how Jost does the right thing in many of the places other geometrics feel awkward.
Looking at the numeral 1 using the weight adjustment on on https://indestructibletype.com/Jost.html, as you increase the weight to about book weight, the angle of the arm of the 1 against the vertical becomes more acute underneath, and thereafter it is noticeable (though doesn't quite feel like it develops consistently). I don't know if this is an attempt to optically correct to keep the join from becoming heavy, but I find the widening of the stroke at the terminus distracting - intuitively I would expect the terminus to be narrowing, not widening here, and perhaps for the angle below to remain the same but the angle above to sharpen, and perhaps even for the terminus to narrow into a point at the maximum weight.
First, I am very glad to have come across your fonts and I like how Jost does the right thing in many of the places other geometrics feel awkward.
Looking at the numeral 1 using the weight adjustment on on https://indestructibletype.com/Jost.html, as you increase the weight to about book weight, the angle of the arm of the 1 against the vertical becomes more acute underneath, and thereafter it is noticeable (though doesn't quite feel like it develops consistently). I don't know if this is an attempt to optically correct to keep the join from becoming heavy, but I find the widening of the stroke at the terminus distracting - intuitively I would expect the terminus to be narrowing, not widening here, and perhaps for the angle below to remain the same but the angle above to sharpen, and perhaps even for the terminus to narrow into a point at the maximum weight.