Moravian Camera support is included in PHD2 v2.6.9dev2 (see https://openphdguiding.org/development-snapshots/).
Linux version of the PHD2 still uses Moravian Camera INDI driver.
Luckily, the INDI driver overhead is much smaller compared to ASCOM.
As Moravian Cameras are fully supported in Linux not only through INDI
drivers, but also using native libraries, native support for Linux
version of PHD2 can be added in the future.