I would have been horrified if the locks were permanent! Given I rent an apartment and I live on my own with no children, I would not have liked to be unable to open my windows fully, particularly given my living room gets to a balmy 32-33 degrees in summer and my landlord does not want to install air conditioning. My building installed their locks a few weeks back and, whilst they are ugly and stick out against the blinds, at least I can open my windows fully during summer nights.
I hope you find a company that will install the locks in way that those residents who do not have children, can still enjoy some fresh air! They’re definitely out there.