Is it safe to touch an occupied nest box?

I recently placed five new nest boxes and one bird house in my parent’s garden. You can imagine my delight on discovering earlier this week that the bird house had just been occupied by a beautiful pair of spotted flycatchers. I have noticed regular movement for the past three days suggesting the pair is building their nests. However there were winds in the past two days and I have noticed that the nest is frequently slightly swinging / moving sideways. Furthermore the bird house is hanging tight on a pine tree branch (around 4 m above the ground) , it is quite exposed to the winds, and is not made of solid wood and has been designed and sold with tiny gaps in the side wall. It is not a huge oscillation and I don’t think there’s a slight likelihood it may fall but the frequent oscillations may be an issue once the chicks are born. The other unoccupied nests boxes are made of solid wood and don’t have the same issue. I am worried that any storm or wind could in future kill or harm the chicks. I am tempted to climb up with a ladder to fix it better with rope and laces, but I don’t want to scare them. Would it be better to wait until the chicks are born, in order not to cause the pair to abandon the nest at this early stage? Or on the contrary by intervening now I may just do them a favor by either fixing the bird house more tightly to the tree or inviting them with my swift visit to find a better option. They haven’t been deterred so far by the oscillations and I would love to see their nest progressing further, but of course the safety of their chicks come first. Any advice would be appreciated.