Fat graft to mid cheeks & temples - are there any risks/side effects like necrosis to the nose with those areas?

Necrosis or death is a pretty definitive term but should probably always be put into context.
When grafting fat only part of the fat will become revascularized and survive in its new location. The remainder of the fat becomes necrotic and is generally absorbed by the body but can lead patients having firm nodules of dead fat, oil cysts and firm areas of scar tissue. That happens during any and all fat transfer procedures to some degree. using good technique for distribution and amount of fat transfer is small enough that it does not create symptoms.
Necrosis from vascular occlusion were blocks of tissue that have end artery blood supply from embolization of the primary artery through injections of foreign material including fat is theoretically possible and has happened. It is by far more likely when injecting fillers since those are injected with relatively sharp instruments even if a cannula is used. fat is generally injected with larger blunt cannulas minimizing the chance of intra-arterial injection. The risk of losing your nose from an attempted fat transfer procedure is probably not something that is worth actually worrying about because of the incredibly low incidence and more of a theoretical risk.
The temples tend to not do well with fat transfer because they have virtually no host tissue to support the graft. The only exception is the graft directly into the temporalis muscle. usually fat grafted in the temporal region is placed superficial to the temporalis muscle and almost all the fat tell us to die overtime.
Delivering consistent quality liposuction and fat transfer result is more difficult than most people believe. Professional work I highly recommend patients stay with the use of fillers. sellers are simply much more precise, predictable and far more forgiving.
If you insist on having facial fat transfer then I recommend being highly selective and choosing your provider.
Have multiple in person consultations at which time you should ask providers to show you their entire collection of before and after pictures.
When reviewing pictures always confirm the exact timeframe between the date of procedure and when after pictures were taken.
When it comes to fat transfer early Postop pictures can look very impressive but these do not represent final results since a significant amount of the fat does not survive long-term. to see honest and accurate results after pictures should be taken a minimum of three months from the procedure but preferably six months or longer.
An experience provider should have no difficulty showing you at least 50 sensor before and after pictures of commonly performed procedures.
Ask providers to show you examples of excellent outcomes, average outcomes and outcomes that did not turn out as well as they had hoped. Always confirm timeframe of when the after picture was taken in relationship to the date of the procedure.
Ask each provider what the revision rate and what their revision policy is. asked to see patients who had revision work or requires more than one session a fat transfer.
To get consistent quality outcomes with this type of work often requires multiple treatments.
The first step is generally to get a good quality assessment. The second to find a list of sufficiently experienced providers. The third step would be vetting those providers and selecting the most talented of the bunch.
Do this by having multiple in person consultations avoiding virtual consultations and I highly recommend patients avoid traveling long distances for elective surgical procedures.
For facial volume restoration fillers are simply superior to using fat.
Best,
Mats Hagstrom MD