+1 from me to all of the above, of course 
But just the other day, I was even thinking of the following, when there might be a particularly complex couple of measures (not necessarily involving an actual time signature change, however)…
How about something like the Score Editor’s “Display Quantize” Tool, where, for example, the Key Editor grid for the most part of a project, in 4/4, can be set to 8th-notes, but, for say, half a bar, we could make use of the grid being in 16th-triplets… just dial in the required grid at the desired position .