It is my understanding that the Lisa GPS device is closely based on the ESP DIY device. If this is correct, then it should be a very straightforward matter that should not take long at all. But we would need to have specifications, comparison data, and preferably a device at hand to test. If the specifications are standard DIY ESP, it would be very quick and simple.
If it is based on the DIY ESP device, then it could become the new gold standard for commercially available devices.

Edit: A quick search reveals picture of two devices under the LISA name. One is obviously a DIY ESP device:

The other one, in the Conners post above has a different display. It may just be a smaller and simplified display with the same electronics, but it may also be a redevelopment?