What are the rules for sideboarding in Riftbound, specifically regarding announcing cards sideboarded, timing, and when choices are locked in?

Ruling: You do not have to announce the number of cards you are sideboarding. Once you present your deck after sideboarding, you are locked in to those choices.

Sequence:

• Players sideboard (no announcement of number of cards required)
• Players present their decks
• Sideboard choices are now locked in

Nuances:

• If your opponent is taking too long during sideboarding, you can call a judge for slow play
• There are no explicit rules in the tournament rulebook about announcing sideboard numbers, priority of announcing, time restrictions, or sticking to choices prior to presenting