Power outages do not damage hardware. Surges occur maybe once every seven years. If having multiple surges, then how many of these have you replaced: refrigerator, central air, door bell, clocks, dishwasher, LED and CFL bulbs, furnace, clock radio, dimmer switches, and the most critical item if a surge exists - smoke detectors?
Second, plug-in protectors do not claim to protect from typically destructive surges. For example, how does its 2 cm part 'block' a surge that cannot be stopped by three miles of sky? How does it 'block' surges?
A surge may be hundreds of thousands of joules. How many joules does that APC claim to 'absorb'? A thousand? What happens when a thousand joules tries to 'absorb' hundreds of thousands of joules? In rare cases, even fire results.
Third, best protection at an iMac is already inside that iMac. Your concern is a rare anomaly (ie once every seven years) that can overwhelm that robust protection. That must be at the service entrance to make a low impedance (ie less than 10 foot) connection to earth ground. To even protect that APC protector. This 'whole house' solution costs about $1 per protected appliance. How much was the APC?
If an iMac needs that protection, then so does everything else. Best protection from any surge is also least expensive protection for everything. How does APC protect a bathroom GFCI, furnace, and all smoke detectors?
Four, UPS is temporary and 'dirty' power so that unsaved data can be saved. It does nothing to protect hardware. Read its spec numbers - hundreds of joules. A number just above zero so that many can be told to believe it does 100% protection. A near zero joules UPS only claims hardware protection where lying is legal - in subjective sales brochures. Not one UPS recommendation cites any number for protection. Many are that easily manipulated by advertising, hearsay, and wild speculation.
UPS power can be so dirty as to be problematic for motorized appliances. Due to robust internal protection, that same 'dirty' power is also ideal for electronics.
BTW, anybody can read spec numbers. A $100 protector is electrically similar to one selling in Walmart for $10. Since so many have no idea what a protector does, then a bigger price somehow means it is better. If better, then one posted specification numbers that said how much better. No numbers posted because a $3 power strip with ten cent protector parts and a fancy paint can sell for $100. Scams are that easily promoted.
As about the only solution that actually protects from surges: a properly earthed 'whole house' protector. It costs about $1 per protected appliance. And is little known to many educated only by advertising.