There are theories that digital is faster, because all the data is stored directly on the Switch. Of course, this has not been confirmed, so take it with a grain of salt.
there is no perfect data about it but almost positive if 1 is faster than the other is for few frames, and that will not affect ur speedrunning
Digital is estimated to be 8-9 seconds faster with loads, but with physical you can get version 1.0.0 which is a 22 second timesave (not counting loads). However, runs using the timesave must be submitted to the true any% board in SMO Category Extensions.
Note that the 22 second timesave Noguy refers to comes from a skip, which isn't mandatory in the physical version nor the 1.0.0. It just saves time at the cost of being in a different category
The switch does not read the data faster on physical, because the data is in a cartridge and not the actual switch itself.