Well I got a good answer to my last question so I thought I would push my luck

I have a generic two button latching footswitch (with LED lights yeah) and plugged it into the back of the DT-25.

Toggle-ing button 2 turns Reverb on both A/B on / OFF OK that works.

Toggle button 1 toggles AMPs A / B as can be seen on the amp display.

Now I have a preset called XOVER CLN CR which has a crunch amp on the TOP path (A)

and a clean amp on the bottom path (B)

I had set it up that FS1 using MULTI could toggle A / B amps. The preset was saved as Clean ON Crunch OFF - so pressing FS1 toggled between CLN and CR. That all worked.

So I took out the FS1 assignments and saved with Clean ON Crunch OFF.

Selected the preset and it played obviously as Clean on the B amp. Now pressing the footswitch it switches to the A amp and turns on the crunch BUT it leaves the B amp ON.

Surely toggle means either A or B so why is the HD500 not following the DT-25? You can see it reflected in HD Edit AMP A goes on / off, B amp remains ON.