One doesn't need parameter mode on a textbutton in 'button' mode because, unlike a toggle button, a simple button has no save state. I had inadvertently, however, enabled parameter mode and discovered that recalling a snapshot now forces the 'button' into 'toggle' mode, overriding the inspector setting. I'm not sure I'd call this a bug — users probably shouldn't enable parameter mode on buttons — but it's surprising behaviour. Here's a patcher demonstrating the issue: