I thought the requirement to notify the LL in advance of intent to file had been rescinded. But if not, then do so anyway, it can't hurt.
Better luck at FOIL? Perhaps. I FOIL a great deal of info from the FOIL office and I have reason to believe they have engaged in a deliberate slow-down or stoppage of my requests. Again, it can't hurt if you wish to try it. BTW, I just send letters and normally do not deal with PDF forms or online forms. Still, why not try? If you do get them, please send us copies.
1. Is it within DHCR's authority to order the LL to supply an alternative means, such as a 'dumb' cellphone, as opposed to a rent reduction?
Yes and no. A service decrease complaint only determines if a service has been decreased. But they will consider what the LL is now providing to see if the replacement is sufficient.
OTOH, an Owner Decrease (OD) proceeding or an Administrative Determination (AD) proceeding can also look at these issues. But normally DHCR does not say something like "Use a Ford instead of a Chevy." The LL would have to say something like, "we have installed a Ford and we believe it is a suitable alternative for the following reasons..." and the tenant can dispute that.