AAOIFI compliance of Islamic mortgage products

I appreciate the work of AAOIFI regarding the establishment of standards for Islamic finance. However, there are many controversial claims of AAOIFI-compliance and some of those have been discussed in this forum as well. Thus, I wanted to know if the mortgage products being offered were really AAOIFI compliant.

Although all the data is not complied yet, I want to share one unexpected finding. Surprisingly, even not a single mortgage company (at least in North America) is compliant with the following section of AAOIFI standard no. 12. I am wondering if you are aware of any Diminishing Musharakah-based company that does not guarantee the value of their equity or in other words compliant to the following section.

5/7 It is permissible for one of the partners to give a binding promise that entitles the other partner to acquire, on the basis of a sale contract, his equity share gradually, according to the market value or a price agreed at the time of acquisition. However, it is not permitted to stipulate that the equity share be acquired at their original or face value, as this would constitute a guarantee of the value of the equity shares of one partner (the Institution) by the other partner, which is prohibited by Shari’ah.

We have started to review companies in the form of a Reddit community (see here). Any comments on our first post will be appreciated.