A SSD versus HD wont make that much of a difference for this game outside of loading times, this is not a game that is a shooter or a platformer [assuming your having a modern HD and not one of those HP Pavilions from 10 years ago, at 3200 rpm- if you do your going to have a very very bad time.] Games mostly store calls in memory, as long as you have 16GB of Ram you should be fine ... if not try to reduce page file limit in your system. DO NOT EVER INCREASE PAGE FILE LIMIT ON A HD, YOU WILL REGRET IT LOL.
This is not good info.
1. They literally state in the MINIMUM specs that you need an SSD.
2. It absolutely makes a huge difference having an SSD versus a regular hard drive - the "pipe" for an SSD is much larger and faster than for an a regular HD.
3. In the event of the system needing to create a swap file - which is a 100% chance with Bg3 - an SSD Swap file will wildly outperform a HD Swap file. The HD swap file may actually crash the system.
Also, if you have not played the full game or helped to make it why would you give advice against what the developers recommend?