If the router loses power it will say rebooted without proper shutdown.
I wont worry about it, just removing the power never caused any problems for me. Had to power cycle a CCR1072 once due to a hard crash and all was fine afterwords
The message in the log is just to inform you that the router was not shutdown by software command but due to loss of power. Everything in the RAM will be lost. That should not be an issue for normal usage of router. Thus, Using option 1 will not harm your MikroTik device.
Personally I don’t like doing it that way, at home maybe fine, but in production, it can cause problems with DHCP if leased addresses has not been written to disk yet, which I think happens every 5 minutes, and then also when properly shutdown via command in routeros