Sorry, but I wasn't able to figure out the reason for introducing a chess timer in the semifinals. Quick thoughts... I guess the root cause lies in:

3. The organizers will make changes to the rules and regulations during the tournament if necessary.

As far as I know, the golden rule of ethics in games highly recommends not changing the rules during the game/competition/tournament/event. Despite this, statement 3 is absolutely logical and necessary if used only in emergencies, serving as a legitimate tool to control/fix/eliminate crucial defects/game bugs unknown at the time when the rules were written. *It seems like it doesn't give the freedom to add/change/improve/simplify existing rules for any other reason. Probably, a change of rules during an event may happen: - as a result of a unanimous request from participants - as a result of a recommendation, if participants unanimously adopted it I haven't noticed mass complaints about the regular timer or a mass request for a chess timer among novices. Furthermore, a couple of facts: 1. All participants agreed and pledged to play in this tournament with a regular timer (obviously, by enrolling in the tournament). 2. Some of them can also play with a chess timer (obviously, by participating in the chess timer survey). For sure, somewhere I am wrong, or I missed something, but I still don't have a clue what the necessity of such a change was. Thanks in advance for clarifying the decision.