Do you leave your platter spinning while switching

My main rig uses a threaded clamp so it's not even an option. Even if it were I wouldn't do it. There's a $5K cartridge hanging there and its cantilever is well placed to get whacked. The miniscule wear and tear on motor and belt from startups could hardly compare with the cost of one little accident...

Even on my old TTs with no clamp and cheap MMs I never did it. Why risk LP or cartridge damage? Unless you're a DJ spinning and mixing live it's a pointless risk.

Startup stress on the motor and belt can be mitigated in safer ways. Just give the platter a helping push.

It was always the done thing with LP12s - largely due to the low torque arrangement. It helped stability to leave it on. The Hercules II is even worse! (Bit of a misnomer that...)
The felt mat had a constant tendency to attach itself to the LP during flipping and occasionally dropped off during the act, causing it to assume a dangerously wide arc towards the stylus! (Another reason for preferring a Ringmat :) I never damaged a cartridge despite this.

So I continued that practice for 25 years until I acquired a Raven, which I always switch on and off as the platter size doesn't lend itself easily to "active flipping".
The Raven's platter is always stabilised in < 1 second so there's no hardship in doing this. If I was going to give it a helping hand I'd have to be quick!!

YES........ I leave my platter spinning when I turn over an LP or put on a new LP. No magical manual dexterity,.. just simple care and an easy touch.

I use a TW deck too, the Raven one and leave it spinning. I don't use a clamp. I tried a Shun Mook weight and could'nt detect much difference. That being the case, it is easy to take a disc off a spinning platter and I agree that constant turning on and off, would logically seem to add stress to the motor and controller.