I performed this exact mod on my Professional Amiga 2000HD Computer.
It works great! It unfortunately suffered from severe Battery Leakage but everything works fine! I was shocked because two other 4000 computers had very minor leakage and both suffered from RTC damage (Would not save time). I guess the larger PCB area of the 2000 came in handy, where on the 4000 the board is smaller and prone to other damage in the surrounding area.
