Does your solution suffer from these issues?
To Fix: List the estimated time to complete, can it be paused or must it be completed in one go, if Video, with or without Audio, just a slide-deck, or something else.
To Fix: Consolidate those nag messages in some fashion. A default should be One a day, with options both administratively and end user to set preferred time and timings to better reflect the local conditions of The Work (the reason the business exists, the training is a secondary support function that won't be allowed to wag the dog).
* If an assignee is only paying attention to email on a weekend for emergencies (because normally a quiet time, vendors who send their marketing on weekends get down voted!) Then any training alerts will only add up to frustration at the training and be invited to junk mail handling process.
To Fix: Default to X Business Days, not X Calendar Days for the training reminders, with those as clearly separate options. And the Business Days needs to reflect the local Statutory and common Holidays, configurable would be nice to add business specific days that are reserved for things other than such secondary functions. Bonus would be for a way to include(sync?) people vacation schedules to pause the training timers over peoples' scheduled time off. Perhaps this could be the way to include Business and/or regional specific off days.
Related to the off hours notifications the system currently does, is that these notifications do trip up against a new legislative trend to protect employees personal time (that whole work/life balance thing). Ontario is the first of the pack to have such legislation and off hours notifications put organizations based here in a rough spot, and we may well be forced to find other training providers that respect the Right to Disconnect.