Here are three studies showing that the 5mg dose of Reclast is not necessary.
There is strong evidence in studies that lower dosages and altered infusion schedules produce very similar results and in one case superior results to the 5 mg dose of Reclast.
It becomes clear from studying the papers that the motivating factors behind the 5mg yearly dose is convenience, patient compliance, money and they say the greater good for the most people. They do not consider intelligent individualized medicine. Nor do any of these papers report anything other than temporary discomfort as a side effect. None of them consider that a lower dose might be safer.

Here are the three papers showing lower doses work just as well:

This one compares 3 different doses and shows that 1mg does well, 2.5mg does best and 5mg does ALMOST as well as 2.5 mg. All three were one dose with result at one year.
https://academic.oup.com/jcem/article/97/1/286/2833555
The next one alters dosing schedules depending on dosage. Combined with the paper above this is great information. They used dosages as small as 0.25mg quarterly with the same result as the large annual dose. It's behind a paywall but you can get a free account and get three free articles a month.
https://www.nejm.org/doi/pdf/10.1056/NEJMoa011807
The third one compares 2mg to 4mg and concludes that 4mg is better. If you dig into the details you see that there is a tiny advantage to 4mg in the spine and a tiny advantage to the femur neck and total hip for the 2mg. Hardly what would make me call the 4mg superior and certainly not a significant difference. The difference in the spine is between 2mg gains 4.86% and 4mg gains 5.35%. So a gain of about 5% either dose. As I said it flips the other way with the hips but they do not consider that even though their study shows it.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8420937/