OK. Thanks, John+Wickberg. Must just be the sluggish nature of Paratext on Linux–click and wait for operation X to happen… Like opening the three-bar menu in the project window, selecting a Note tag from the dropdown, even typing at times (type a word and wait for it to appear on the screen to see if it’s spelled correctly). And the only windows open are my project, a text collection (with five resources), and the source language window. Sadly, Fieldworks on Linux is worse, but much the same–a lot of waiting for things to happen. In fact, the Linux version is so slow, I run the Windows version of Fieldworks in a virtual machine…
I’ll ask what seems to me to be a related question: is it normal for a program to use 25% CPU (i.e., 100% of one core) for much of the time it’s running? According to System Monitor, Paratext does… I don’t have the newest machine (Lenovo x250, i5-5300U CPU @ 2.30GHz), but with 16 GB of RAM it does OK with most other programs. Of all the programs I run, Paratext strains the machine most–even more than Fieldworks in a VM.