Five people desperate for more XP and faster decide to vote up the same node. The consequence? A node gets a few extra reputation points. If they get too desperate, what happens? They run out of votes. So, they likely actually apply the votes they have to the better of the nodes they run into anyway, but maybe not. So the down side is trivial and even with the wrongly motivated, there may be no down side at all.
Five people desperate for more XP faster consider a node with reason "spam" (because they are sick of seeing this (newbie|windows|moose|...) whining being spammed all over the place) and vote "reap". The consequence? A node gets reaped. If they get too desperate, what happens? They don't run out of tokens for considering nodes nor for voting on considerations.
Just "XP for consideration" is a horrible idea. No, I don't see that happening any time.
No, I don't think we should have a limited number of tokens per day that one can apply to considering a node or voting on a consideration. Even if we did that to try to match the XP motivation for voting, I don't think the results would be good. At least not if it is mixed in with the XP system. A parallel but separate (and different in several ways) system of "start slow with consideration" that fairly quickly moves to "unlimited" could have value (but still presents problems).
The primary evil I've found with consideration is lack of care and contemplation. Motivating "more" is not that useful of a goal with consideration.
I've kicked around a feedback mechanism for consideration that relies on rewarding "good" consideration and punishing "bad" consideration. The punishment would be a temporary suspension on one's ability to consider nodes / vote on considerations. The determination of "good" vs "bad" would be by the community. If you consider a node for "edit", then "keep" votes would count against you, for example.
But I'm seeing fewer problems with consideration already. It appears to have worked to some extent to put emphasis on things like "don't consider the small stuff", "don't consider without a specific action and a strong justification / motivation because the person considering the node has to do the hard work; don't float trial balloons and expect the voters to do the hard work of actually making a decision before clicking one button", "seeing a consideration reason in NTC often means it was a /bad/ reason", "considerations automatically expire".
So the determination I made long ago of "an effective system is too much work to implement for the benefit it would provide" is even more true now.
A system to encourage paying attention to what the community wants might have value. But I think the current "the motivation for doing consideration work is not personal gain" is still working pretty well. And the considerable work to revamp in a way that won't be detrimental makes it far below several other much higher priorities.