I feel like I've never gotten a compelling explanation for why Nastaliq is hard/unavailable. I'm not an expert on abjads, but it doesn't look harder to render then Naskh (and it self-evidently is possible since the fonts exist). Does anyone here know why they make it difficult? Urdu is much less obscure than, say, Sharada or other languages with Unicode support. I think Punjabi is also often written in Nastaliq when it's not in Gurmukhi or Roman.
>compelling explanation for why Nastaliq is hard/unavailable
There are many high quality Nastaliq fonts available. You can install them on your computer and use them easily in whatever software (example office apps) allows you to set the font.
There are no technical reasons preventing the use of Nastaliq fonts everywhere. Only product design decisions by big tech.
My guess would be line height is a challenge and Naskh already exists. Then probably because these scripts are not used often in the places that are centers of software/OS development.
In Naskh, each letter has only four forms (for the most part — there are a few ligatures etc. but I think ‘only four forms’ remains basically true). The choice between forms is determined almost entirely by position within a word (initial/medial/final/isolated). All the letters are aligned along the baseline and connect to each other in basically the same way.
By contrast Nastaliq is a much more complicated style. Many letters and letter combinations take on several different forms depending on which other letters surround them. Letter joins are usually diagonal, so letters earlier in a word need to be shifted above the baseline by a variable amount. Having to shift letters vertically as well as horizontally greatly complicates other aspects of the style too.
(I recall seeing a nice table some time ago showing all the various different possibilities for letter joins in Nastaliq. Unfortunately I can’t seem to find it again. Still, you might get some idea by consulting the documentation of one of the existing Nastaliq fonts, e.g. Awami Nastaliq: https://software.sil.org/awami/what-is-special/)