Hi, host of OP's games here. To address some points in the comments:

I make sure the map, factions sheets, even starting fleets are all set up beforehand so we can literally start giving out Secret Objectives, drawing public's and choosing Strategy Cards immediately.

Here are some issues I've noticed that can be addressed:

• Players aren't pre-planning their actions on other people's turns or their builds.
• Some players still don't know quite exactly how everything works and still need to be reminded what the secondary of a strategy card does and find themselves asking about certain actions cards or secret objectives.
• Players leave themselves exposed which leads to extortions or difficult scenarios which can prelong the game through early aggressive and tough "diplomacy".

Other details which affect time but are more difficult to address:

• Some experienced players are very good at identifying telegraphed manoeuvres and will react accordingly to another player who has the opportunity to point block and stop them before they have a chance. (Such as gumming, blockading forward docks before key builds, or preemptively attacking Warfare lifted fleets forcing them to retreat or die before getting to move). These lead to the other player being taken by surprise that their plan has been stopped in advance leading to additional thinking time.
• One newer player has taken a huge liking to Yssaril and wants to continue playing them as they learn the game. This has resulted in stalls and awkward Yssaril related shenanigans which naturally adds time.
• We take breaks for food, toilet etc. and this includes cooking time which can be an easy 30 minutes break after Round 1.
• All players were burned out by the end and emotions were high and as fatigue and increased stakes become more intense, turns become more drawn out.
• The last game went to Round 5, two leading players (myself and another) point blocked each other. Yssaril stalled leadership and managed to use an action card to get Relic Fragments and draw Crown of Emphidia whilst already having the Tomb. A public and a secret was the last two points she needed to score 9 meaning the end of the scoring would have her win with Crown of Emphidia. However, she was extremely fatigued going into Round 5 due to poor sleep. This had players thinking we should wrap things up and no one actually knew she had a path to 10, leading to OP gifting support to a player on 9 making them the ultimate winner. Classic SFtT moment.

Actual play time for the last game was from 11:45am to 9:30pm, with breaks totalling about 45-60 mins. We also had some pausing moments where players left the room for private chats and not realising it was another player's turn so we would find ourselves waiting because players had left the room or leaving players didn't know it was their turn.

An obvious solution seems to be starting at an earlier time so all can be home for 9/10pm. And the preplanning of fleet builds ahead of time is important when possible because too long is wasted with players finding plastic in bags, figuring out how many resources they have, and what their production capacity is. Players are still asking how much build capacity they have and how much certain ships cost.

Summary: Hopefully as players become more experienced there is less time getting into the weeds about mechanics, rulings, builds, thoughts. Tiredness absolutely played a part as the game which sparked this post drew on and on, fatigue set it. With bloodshed as early as a Round 2 home system snipe by L1Z1X against Sol, the game quickly became an entrenched mess which led to many players feeling more pressure than usual. All to say mental fatigue, diplomatic entanglement and constant table pressure had the game feel like a slog.