I had started studying this point recently and was confused by some of the sample sentences provided. For eg - consider these sentences
大事な相談をするところにじゃまが入った。
宿題をするところで、友達から電話が入った。
How is the particle after ところ decided? And why is に used in the first one while で is used in the second one? Why not the other way round?
Did you go through the ‘readings’ section? How and when it’s used and what the particles indicate is all in there and explained better than I could here.
Maggie Sensei is the better reading IMO. Seems the nuance depends on the state of previous action which makes sense here. Would make sense to have a BP note here.
*When two things happen at the same time / when you focus on the time more than location.
*Indicating the location / time / situation / When it fills certain conditions~
Weirdly enough, ところで is its own separate grammar point.
I think those behave conceptually similar as an interjection of some kind, even with the “By the way” new topic switch.
There is also this one:
Verb[た] + ところで ~ ない
It’s interesting because you can now create a noun phrase much like こと・の but as a conditional. Seems there are whole family of て(も)で(も) endings that behave similarly with a “even if” nuance.
I hear one often. Perhaps there are more.
ところではない