I clearly understand how instant sympathetic casting functions, as sympathetic penalties apply in the same way that penalties are applied for changing the secondary Factors of the spell (Duration/targets/Etc. on spells where they are not marked as primary). Casting sympathetically would obviously apply the penalty identically.
Where I have a question is when you start looking at the rules for extended spellcasting, and it starts to raise some difficult points. This is doubly true when you remember the rule for extended actions in the Core Rulebook that states that the number of attempts on extended actions you can take is limited by your dice pool.
During extended spellcasting, all factors are treated equally, adding additional successes to the required total. There is not a listing specifically for sympathetic range adding successes however, despite it using an identical table to secondary factors on the penalty scales for instant casting. Do you continue to use penalties for extended sympathetic casting, identically to instant sympathetic casting? If so, does this mean that sympathetic "attacks" would almost certainly require disciple and lower level mages to resort to cabal level group rituals, since the sympathetic penalty would often reduce the extended casting based on the core rulebook extended action rule to a single attempt?
Is there a part of the sympathetic casting rules I'm missing from a book besides the core Awakening book?
Edit, Added Info: Rereading the Tome of the Mysteries I see that they clarified that it is the BASE action dice pool that determines the maximum number of attempts available to a Mage casting an extended spell. This changes things somewhat, so I felt it was useful to point this out, though the core question remains, do sympathetic penalties remain penalties when used during an extended casting, and if so what effects does it have on extended attack magic (Which is specifically mentioned in Tome of the Mysteries as often being Sympathetic, despite what seems like possibly tremendous penalties after all the bonuses and penalties are combined).