OK I got come clarification: @vince31fr is using https://github.com/krazey/ims as the base for the IMS reimplementation.
As it is only for a few series, and only officially for A16 / LOS 23.x (thus iodéOS 7.x), it means it will only be made available for the S10 series (including Note 10) devices to start (v7.7 - currently in beta). Later, S9 series (v4.x) and other devices with v7.x will be added, if all goes well in the next development cycle. As the older “A series” devices are v2.x they may not be possible. A52 is v6.x not certain about that one, I guess we wait an see.
Of course any unofficial builds would need their maintainers to implement, as @ronnz98 is already doing for his.