OP discusses the below-the-baseline issue describes it as “annoying but not a deal breaker”.
If this is a deal breaker because you’re aspiring for Edward Tufte levels of visualization purity, OP also offers an alternative that omits below-the-baseline U+2584 and U+2588. The trade off is having fewer unequally sized buckets for the data.
(Could there be font faces without this rendering issue?)
> (Could there be font faces without this rendering issue?)
A comment under OP suggests that the rendering issue is font-dependent. When I view a Unicode sparkline on a test page [1], the rendering issue occurs using Arial, Courier New, Gill Sans, Helvetica, or Times New Roman, but appears to be fixed if I use Georgia, Menlo, or Comic Sans.
If this is a deal breaker because you’re aspiring for Edward Tufte levels of visualization purity, OP also offers an alternative that omits below-the-baseline U+2584 and U+2588. The trade off is having fewer unequally sized buckets for the data.
(Could there be font faces without this rendering issue?)