optional undo

Agree 100%

Consider a checkbox to enable/disable the undo feature. I want it, but other players may feel differently.

Agreed. Undo should be mandatory for all games if hidden information isnt revealed.

Rejected the most upvoted issue because "its my first time and its too hard" doesnt fill me with confidence here. Perhaps see if there's a more experienced dev that can assist.

I agree. Many games need this feature

An Undo action or confirm step is very frequently requested for adaptations where it doesn't exist, and I frequently see developers lean on the guidelines as an authoritative answer to every situation. Any experienced designer will tell you there is no such thing as a one-size-fits-all answer. The entire intent of guidelines is to make better adaptations, and it is on the developer to decide where that line is.

Are players having to click confirm buttons too many times?
Are players intentionally playing bad moves or moving pieces around in order to "think"?
Are players frustrated that the interface wouldn't let them take the turn that they wanted to take because they made one misclick? (definitely sounds like the case here).

There are a few ways you could go about this, but the simplest to implement and the one I would recommend would be database undo.
en.doc.boardgamearena.com/Main_game_logic:_yourgamename.game.php#Undo_moves

This would undo your entire turn. Canceled notification log items would disappear and there would only be one item saying "<player> cancels their move". The guidelines do mention that this is a heavy-handed solution because it saves and restores the entire table's data, but it is consistent with how many other games are implementing undo.

A more difficult to implement alternative would be an incremental undo ("player undoes worker action"). This would require storing individual actions taken this turn in the database in some way and creating a coherent way to represent undo on the client side. This is how I implemented incremental undo for tile placement in Off the Rails, but it does have the disadvantage you mention of creating a log entry for every action that is done and undone.

The basic implementation of database undo actually only requires a few lines of code.

$this->undoSavePoint(); at the beginning of a single player's turn, an undo button added to the action bar (possibly with a modal confirmation), an undo action added to action.php and added as a possible action to the state, and $this->undoRestorePoint(); if the user takes the undo action. See La Granja, Teotihuacan, and Off the Rails (mine) for publicly accessible precedents.

I do not believe an end turn button violates the intent of the BGA guidelines for multi-step turns. I have written a defense of this position on the forums here: boardgamearena.com/forum/viewtopic.php?f=12&t=16770

Of course, every game is different, and if an end turn button feels like too much of an extra step, you could investigate the "request undo" checkbox precedent established in Teotihuacan. This would require refactoring to add an extra state, or to add an extra argument to each player action.

database undo is not supported in multiactiveplayer states. There can be only one persistent active player between any two points where undoSavePoint and undoRestorePoint are called. From my understanding of this game, it seems pretty rare that the multipleactiveplayer state would require multiple actions, so you'd probably be fine without an undo here. If it feels like it does need an Undo to be consistent, it might be better to cycle through players in a single action. La Granja has a game option for this, but that might be overkill here.

No notifications are necessary to restore the game state. undoRestorePoint automatically handles this :)

I forgot to add that rolling out database undo will break games in progress, so it's best to do that now while it's in Alpha.

Wish it was like in carcassonne 3 tiles in hand. Be able to change mind about which of the three tiles and try them out on the before you confirm. Then I guess the undo would be not necessary.

An undo button when placing a tile would be nice so before you confirm placement you can choose a different tile.

I think that would be enough and a more practical solution (for players and developer) to have the ability to change the worker tile just before choosing the jungle tile