Useful calcs/equations:
Old 3.0 tp:
- time to next cast = 12s from placement, fixed
- experienced down time = (10s - usage time) + 2s
- where usage time is in [0s,10s] which represents time spent actually using it and the last 2s is the remaining cd when tp duration is spent.
- 0 <= experienced down time <= 12s
infinite tp 
:
- time to next cast = uptime + 12s
- experienced down time = 12s + (uptime - usage time)
- which is unbounded above
- but already the MINIMUM experienced down time here is greater than or equal to the MAXIMUM down time of old 3.0 tp
what changes we want should try to use the above to compare the standards of cast frequency and experienced down time.