Worked through a fix for the flickering of the EquipmentUI panel attached to the Inventory panel when hovering on and away from the Loot Panel when using the auto-hide feature of SpiffUI Inventory (sandbox option ‘Enable SpiffUI Inventory Rules’). All code changes are in the SUI_InventoryPage.lua file:

First need to decouple both panels autohiding together, by removing:
line 223: self.friend:setVisibleReal(spiff.Conf.invVisible)
line 244: self.friend:setVisibleReal(true)

Second change is related to the update function (starts line 567), and further prevents a trigger of the Inventory panel when interacting with the Loot Panel:
Adding/Changing the lines starting at 720 (would end at 729):
if self.onCharacter then
if self:isMouseInTop() or self:isMouseOverEquipmentUi() then
self:Collapse(false, "MouseMoveIn Player Inv")
self.autoHide = true
end
else -- For the loot panel, it should only show if its top is moused over.
if self:isMouseInTop() then
self:Collapse(false, "MouseMoveIn Loot Inv")
self.autoHide = true
end
end

Remove the following:
line 733 - 734:
else
self:Collapse(false, "force visible")

These following changes allow the auto-hide feature without the flickering of the EquipmentUI

Also possible fix for autohide not working when drag to floor

Not sure if intended with auto-hide, but dragging an item to the floor causes the inventory/loot panel to remain open even with auto-hide enabled. Will collapse upon mouse clicks. The following changes to the SUI_InventoryPage.lua file can fix this

Within the function ISInventoryPage:update()

... (existing code) ...

if not self.isCollapsed then
if not self.fVisible then
if (not ISMouseDrag.dragging or #ISMouseDrag.dragging == 0) then
if self.fromDrag then
self.fromDrag = false
self.autoHide = true

if not self:isMouseInBuffer() and not self.friend:isMouseInBuffer() then -- Check if mouse is NOT in either panel
self.holdOpen = false -- Ensure holdOpen is reset to allow auto-hide
self.wasDrag = false -- Also clear wasDrag if not hovering over a friend
else
self.wasDrag = self.friend.mouseOver -- Keep existing logic if hovering over friend
self.holdOpen = not self.wasDrag -- Keep existing holdOpen logic based on wasDrag
end

end

…(rest of code) …
end