Bismillah.
You may have seen this already but if not, you will find below a set of hyperlinks to most of the Arabic works by Imam al-Haddad. The print is beautiful and suitable for students. I have hard copies at home so I can attest to the quality. Most of the texts are unvoweled but where there is ambiguity in the meaning or morphology, the editor has included tashkil.
I'll give you one example. In his Kitab al-Hikam, it says:
النائم يوقظ والغافل يذكر ومن لم يجد فيه التذكير والتنبيه فهو ميت. إنما تنفع الموعظة من أقبل عليها بقلبه. وما يتذكر إلا من ينيب
يجد is yujdi and the ya is madmumah, the jim sakinah and the dal maksurah. This is helpful for both the intermediate and advanced level student. Most people will assume it is yajid. Second guesses would include deeming the verb naqis, but in a different form, mithal (w-j-d), ajwaf (j-w-d), muda'af (j-d-d), etc.
يذكر and يوقظ are voweled in the passive voice.
ميت is mayyit with a shaddah.
etc.
You may wish to share these links with students. See below.
wassalam alaykum
yusuf