The current Smooth operation on the Guide Groom node works quite differently than how I'd expect it to work as it averages surrounding guides to shape the guide. This makes it hard to smooth a guide itself independent of other guides which is something that usually happens when grooming long hairs. Is it possible to add a per-guide smoothing operation as a modifier, for example by holding shift + LMB, the brush switches to smoothing mode. Shift + RMB can still be used to change brush size (or vice versa).

Best to submit feature requests to support@sidefx.com so they can be properly tracked. Start the topic with “RFE:” (request for enhancement) so it's clear what you're asking.