I'm tempted to try the Beta for Android 12, but the info supplied says "Samsung expressly disclaims all warranties of any kind, both expressed or implied". As my phone is less than a year old and purchased directly from Samsung, would I forfeit my device warranty early if I took part in the beta trial?
Yes because you are risking your device with something that could potentially render it broken in some way. Despite the fact the beta is offered by Samsung themselves, it is essentially the same as flashing an unsupported ROM from the xda-developers forum. Best leave well alone