At 1000 Hz, the harmonic content is likely reduced to the point where it's not painful like it is at lower pitch settings. And few, if any operators will use a CW pitch that high in frequency.
After using Maestro for two months, this issue has been my chief complaint, closely followed by the dirty/fuzzy receive audio from the Opus CODEC which, is apparently not adapting to link quality. This issue is not limited to Maestro, it can be heard when using SSDR in remote mode as well as the K6TU iPad app. So, it's not hardware-specific. I want to be clear on this point: it's subtle but it's definitely there. See: