ESP32-WROOM-32 v/s ESP32_WROVER

[Vedashree]

Can someone clarify the following queries. It would be a big help.

1Q) In ESP32-Lyra V4 schematics, ESP32_WROVER was given as main IC, can I know why ESP32-WROOM-32 was mentioned although it was indicated as (NC)?

2Q) Can both ESP32-WROOM-32 and ESP32_WROVER support AVS (Alexa Voice Service)?

3Q) I wanted to use ESP32-WROOM-32 instead of ESP32_WROVER (since it was out of stock at the time I searched) in my application (which supports AVS). What are the major differences between ESP32-WROOM-32 and ESP32_WROVER?

4Q) Is the requirement for PSRAM compulsory to store speech commands for AVS (Alexa Voice Service)?

Thank you,
Vedashree.