Suggestion 1:
A timer begins counting down at the beginning of a dungeon boss fight. It looks like this:
https://i.postimg.cc/fWrR22gx/P1.png
When this timer expires the boss dies. The party is then rewarded with loot normally.
Suggestion 2:
Let the dungeon stay open longer or possibly just remove the dungeon lock.
Suggestion Benefit Examples:
Benefit Example 1:
How it is:
2 friends want to play Shadow Sanguinary. They wait for 30 to 50 minutes then turn the game off. 
How it should be:
2 friends want to play Shadow Sanguinary. The 2 friends (1 Healer and 1 warrior) then teleport to the dungeon entrance and play as they like with their strategy of choice. Each boss is dead after 5 minutes due to the timer. The two friends collect loot as a party normally would after 15 minutes. 
Benefit Example 2 (Dungeon Lock example):
How it is:
A player that is doing really high DPS in fusion lab is (5 person party) is mad because a new tank is struggling to hold aggro. The raging player then turns the game off in frustration. The party kicks and recruits a new team member but the healer is mystic which is unable to pull the new party member into the dungeon. The newly recruited party member is forced to wait and watch while the other 4 party members struggle for 8 minutes.
How it should be:
The newly recruited party member simply walks into the dungeon and joins the fight. The new party member has really low DPS and has no idea how to use skill rotations and has very little gear knowledge. This is okay because the boss will die in 5 minutes due to the timer countdown anyway. 
Benefit Example 3:
How it is:
I want to play and my dungeon queue just came up but I don't know if the party can finish the fight in 10 minutes because I have to get ready for work in about 15 minutes. 
How it should be:
I want to play and I have 15 minutes and I know if the party does not kill the boss in 10 minutes the timer will so it's good. I can play then go to work. 
Benefit Example 4:
How it is:
My fellow friends, we cannot find a tank for an hour now and there is no way I am going to do any middle tier dungeons without tank because our DPS drops to poo when we have to constantly run for our lives and chase a boss to hit it. 
How it should be:
My fellow friends. There are no tanks left in this game because you are all cowards. However, all we have to do my friends is teleport to the dungeon entrance and go in and then fight until the timer runs down. We then get our loot. The timer will lead us to victory. Let us play this content as one. 
Benefit Example 5:
How it is:
3 total noobs enter catacombs. They only know how to run and press 2 or 3 skill buttons. They run in circles as they are chased. 1 quits. The other 2 noobs don't know how to recruit but they keep fighting. Finally the priest realizes 8 minutes into the match that she can use plague of exhaustion debuff the boss which raises the noob attack over all by .004%. This will lower the dungeon completion from 13 minutes down to 12:36. etc. etc.
(lol. yes, it can get that bad and it happens everyday). 
How it should be:
My fellow noobs, no matter how bad you may be remember this: the timer will save you. In the end, one chest with one precious frost flower pollen gear piece will be yours. I swear it. 
Benefit Example 6:
How it is: no one in my guild is online or geared up anyway. I have no one to play with.
I am going to lost ark. See ya.
How it should be: I will teleport to these dungeon entrances and play these middle tier dungeons alone like a boss and explore this content on my own for fun. The timer will give me my loot after 15 minutes. Life is good. 
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Example recommendation timer countdown for bosses:
Macellarius Catacombs: 3 minutes is about all a noob will tolerate fighting these bosses. Especially the first one.
Thaumetal Refinery: 3 minutes each. If they can't kill that Gorilla in 3 minutes they really probably need help before they uninstall and go to lost ark (if they haven't already).
Fusion Lab: 10 minutes.
Forbidden Arena: 10 minutes.
Shadow Sanguinary: 5 minutes each = 15 minutes total.
etc.
A quick note on dungeon locks:
Removing the dungeon lock completely could be exploited by staggering apart timers on dungeon fights then inviting friends to dungeons right before dungeon timer counts down. My recommendation would be to extent the amount of time before the dungeon locks until about mid game. By then most of the rage baby drops have already rage quitted and other players are not punished.
Closing:
Thank you for reading my suggestion. I feel that this will really open up the patch and let people explore content a lot more. I think this would be of extreme benefit at this point in Tera's life cycle due to the continually dropping player population, long queue times (sometimes no tanks, healers, dps ,etc.).
Feel free to discuss the idea good or bad. Thank you. 
