About the ROI, it really is gone now, but you have to take into account, that BTC price will likely go up, so even if you lose now, you can gain later. Especially if you've already made an investment in the HW, chips etc.
An investment that doesn't earn back its principal is called a
loss.
And about changing the HW for next gen Avalon chips (or any other chips), who is going to make this? Bkk seems to be gone (probably get sick of all the events regarding chips delivery, companies taking advantage of opensource project and giving nothing back) and there seems to be noone (even in the group of those companies, which started their business on this) who is able to make this change.
That's a great question! I don't have the answer, but I'd love to get some discussion going and find out.
is based on klondike original but with some major modifications. I think it is also capable of using Avalon Gen2 chips. The main problem is that such a development is very costly and you get nothing back from it. Noone pays the development equipment nor the hundreds of hours for the project. The problem is also that there a newer chips available before the old ones are shipped. This was the case with Avalon Gen1. So such a development ist mostly not worth its time.