Yeah, I think we're pretty much in agreement here.I would say that this is implicit in the way the game treats tasks the core resolution mechanic. A task isn't a check and the check is divorced from the fiction. The existence of a check means there is a task being performed that has an uncertain outcome and a meaningful consequence for failure. You can have a task without a check, but not a check without a task.
To me, this just doesn't follow. What about the narrative of a character that's muddling through some task and is likely to fail, only to receive some burst of inspiration or divine guidance at a critical moment that allows him/her to succeed? That type of intercession can come at any moment.Though those spells, feats, and features do affect the check and thereby possibly the outcome of the task, there is no way for a character to know at what point in the task the check is being made (since, again, a check doesn't exist in the game world). What's going on in the game world is that a cleric is offering guidance on a task, a bard is offering inspiration in general which may be applied to a task, and lucky is just the natural state of the character which has the benefit of affecting checks. Therefore, it makes sense that these things must be in effect at the start of and by the end of the task to affect the outcome.
I'm not exactly sure what the common problems are, other than the report of "spamming" which started these threads. It seems to me that "spamming" is kind of what cantrips are made for, so I'm still not sure how it's a problem. I'm certainly not recommending any changes to the spell. As I posted in the other thread, I think transparently known DCs, coupled with no imposed restriction on casting after a check has been rolled, immediately reduces the number of ability checks for which guidance will be (perceived to be) useful.When handling it like this, which I believe is perfectly in line with the core game mechanics, the problems commonly reported with spells like guidance simply go away without a need to change the spell at all. If the task takes longer than a minute, for example, guidance just isn't going to help and it needs to be cast before the task is undertaken. This immediately reduces the number of tasks for which guidance will be useful.