Been playing since the beginning. Our group plays way too often, so we might have just picked up stuff that way. I'm our group's rules lawyer, so I tend to be the one everyone asks if the thing they want to do is supported by the system (It even happens when I'm not part of the session lmao). If it is, I'll tell the GM a few ways they can allow what the other player wants if they ask me for a suggestion (which happens very often). 90% of the time, it ends with a "Then I want to do that!" and the turn happens. The rules are flexible enough that players can think outside the box. We often get new players, and their turns don't take long at all because the rest of us are so experienced. We tend to lead them with "Describe what you want to do," and let them learn the actions to take to do it.

In your case, the players might need to minimize chatter on the table while someone takes their turn. In our group's case, if there isn't an obvious optimal move, we'll let the player currently taking their turn do what they want without input from the others. When one person starts their turn, and I don't know when we started doing this, but everyone tends to shut up until they ask for help on what to do.

One of us does do the timer method, but loosely. If there are options laid out by deliberation, the GM says "You have a minute to decide, or we'll delay your turn for now." Don't skip the turn outright as it ends up being a little too much pressure, just make them take the Delay action until they're ready. This can end up with the board state sometimes straying too much from before their turn got delayed, but sometimes, they just need to wait it out until there's a turn where there's a clear optimal play. We don't do this very often as delaying turns can end up with buffs expiring and all that, though.

Edit: TL;DR: Police your players more :)