As many people who do Synergy know, clicking on the Furnace takes a while to bring up the menu and after performing an action it takes a while for the menu to reappear (this is related to your connection), and in turn affects everything about synergy. Depending on if my internet connection is good, I can have 4-5 chances to 'thwack' the furnace prior to an explosion, but on bad days I can struggle to get 3.
From a technical standpoint, every time you interact with the furnace (click/perform action) the client sends unnecessary packets which will only make the menu appear when they have received replies. Whilst I understand the need for ensuring that menus cannot be hacked to allow massive amounts of actions automatically, the cost is high since the menu takes just so long to appear. Packets should only really be sent for actions performed only, rather than these extra packets concerning menus.
As SE prepares to release augmentable via synergy 'good' gear, I can see the issue of being how good you are at this time critical craft being more dependant on something you can't control than something you can.