The RJ Professional is an MSFS-2024 native product, meaning that the aircraft package was built natively within MSFS 2024's package system rather than being a ported MSFS 2020 package. Some MSFS 2024 features, such as an updated LOD system and different texture formats, are automatically enabled when building a package in MSFS 2024, whereas other features, such as walkaround mode, require additional development time to implement.
As the RJ Professional was the first of our airlines to be upgraded to MSFS 2024 native standard, we hadn't yet investigated the work required to add walkaround mode support to the product, so it was not implemented in the v1.4 update.
We have since added walkaround mode support to our 146 Professional and F28 Professional products in MSFS 2024, and it will also be added to the RJ Professional in the next update.
Mark - Just Flight