My bad, I was not supplying the environment variable in the correct way. It is working via mpiexec now
/opt/ParaView-5.10.1-egl-MPI-Linux-Python3.9-x86_64/bin/mpiexec \
-env VTK_DEFAULT_EGL_DEVICE_INDEX=0 /opt/ParaView-5.10.1-egl-MPI-Linux-Python3.9-x86_64/bin/pvserver : \
-env VTK_DEFAULT_EGL_DEVICE_INDEX=1 /opt/ParaView-5.10.1-egl-MPI-Linux-Python3.9-x86_64/bin/pvserver
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 510.73.05 Driver Version: 510.73.05 CUDA Version: 11.6 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|===============================+======================+======================|
| 0 NVIDIA A100-PCI... Off | 00000000:04:00.0 Off | 0 |
| N/A 26C P0 34W / 250W | 15995MiB / 40960MiB | 0% Default |
| | | Disabled |
+-------------------------------+----------------------+----------------------+
| 1 NVIDIA A100-PCI... Off | 00000000:05:00.0 Off | 0 |
| N/A 26C P0 34W / 250W | 23557MiB / 40960MiB | 0% Default |
| | | Disabled |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Processes: |
| GPU GI CI PID Type Process name GPU Memory |
| ID ID Usage |
|=============================================================================|
| 0 N/A N/A 3198 G ...-x86_64/bin/pvserver-real 15995MiB |
| 1 N/A N/A 3197 G ...-x86_64/bin/pvserver-real 23557MiB |
+-----------------------------------------------------------------------------+
Thank you.