Well, the 145 is still produced as BK117.
Thats why i.e. the CWP (Central Warning Panel) was put above the monitors of the Helionix System.
You don‘t need it, cause every caution will appear on the master list but without, Airbus wouldn‘t be able to produce the 145 on the 117 papers...
Still, there are quite remarkable differences between the B2, C1 and the 145 which I all flew/fly.
Things which won‘t bother you on the daily Job but are important in case of system failures.
Differences in Overspeed handling, differences in hydraulics just for example.
The amount of training needed? Well difficult to decide. I guess, if in doubt, play it save which is a pain for some but might give deeper understanding for others...