I also think HF's communication is sorely lacking but I am really hard pressed to see how suing a co with no funds is going to help anyone at all
I don't want to bring Hashfast down either, but I think suing them is a legitimate option. HF raised money from investors (not from sales) for the startup costs, IIRC to the tune of around USD 600-700k (check me on that). Now surely they have dipped significantly into the sales money, but they have also sold four batches of machines. I'm pretty sure Hashfast does have some significant money and that it does have some other potentially valuable assets (IP).
IMHO, the obvious path of least resistance for Hashfast, and the option that costs least, is to massively up the MPP - deliver more hashpower faster to MPP customers. Yes, that would piss some non-MPP customers off, probably, but on balance, considering the lawsuit risks and reputation destruction potential of failure to deliver (which is obviously already beginning to harm them) ...
The two problems I see with, say, HF doubling the MPP hashpower and committing to an earlier miniboard delivery date are:
1) Lack of demonstration that the equipment reliably works, and;
2) Hashfast's general credibility is so bad at this point that a lot of people with orders may choose to simply not believe them and sue anyway.