I definitely agree and a temporary solution should definitely be added while we wait for them to implement a new system. The fact that this issue has been going on for over a year is just outrageous.
A PM would most likely work just like old Post Approval, so I do not know if it would be much of benefit since the same issues would be present once more. A solution that could possibly work is the ability to continue the automated ranking-up system (with manual approval before promotion). Having suspended the promotion system, many uses who would otherwise quality for promotion are stuck in the Member rank and are restricted from performing Regular activities on the forum, even though they should be. I am certain many people are eligible for promotion to Regular, and opening up the promotion system once more would assist in this issue.
If the promotion to Regular is not working as well, a combination of the two could be implemented. A third rank could be added to the whole, between Member and Regular. The rank would have the same permissions as the Member rank, with the exception that it could make a request to a new Post Approval team. The rank would only be obtained by active or veteran members of the DevForum who might not quite qualify for Regular yet. That way, the Post Approval team is not flooded with hundreds of requests (of which many are spam or junk), as the only people who could use the Post Approval process would be people who have build a small trusted reputation on the forum, whether by their activity or the topics and reach they have created. This would also fix the ranking issue, as the rank “Member” tends to have a huge mix of people, from people who just joined the DevForum to people who have been active here for a year and are not ranked Regular. People who are active and have somewhat build up a reputation would fall under this rank, which would give them the trusted privilege of making a Post Request.
Either way, some temporary solution is definitely needed in the meantime as I do not believe that Roblox will be releasing their new system any time soon.