Sounds like there is enough interest to get at least a first batch of chips.
Faster response rate is about twice as fast as the original EOB. May go a little faster on that, but want to keep it smooth.
You can still program the chuff rate for steam, if an external chuff is not used.
If you are doing lash-ups, you would have to make sure the tack strips are the same so the engines don't fight each other.
Yes, they will work in a drop in board.
I will do some final tweaks and order some chips. Final version will probably be ready in a couple of weeks.
