Regarding ELC slide rule:
There is absolutely no correlation between the amount of cap dollars that slide from year to year. The investment levels only dictact how many years the team has ELC slide eligibility. $5 million for one year, $8 million for two. It’s intention is to simulate a benefit to investing in player development and supporting your draft picks with good coaching, systems, etc.
As long as you have the required investment at the time of the ELC signing and they stay under the thresholds listed (under 21 years old and 9 NHL games or less) you can have as many ELC contracts slide as you want.