This whole 30 min buff idea backfires, the only skills that have value with that are party buffs and even then it can be argued that players can exploit it with slave characters.
When a self buff has 100% uptime you have two balancing elements - death and consumption - but this is made pointless when the difference between cooldown and duration is too large. Using a practical example, Gung Ho has 1 min cd and 30 min duration, if you die on the first minute of Gung Ho you’ll feel a power drop until the skill is available again however the other 29 min taking the worst scenario, even then that is an unusual occurrence and may happen with lower cooldown time instead of the ‘use and die instantly’ case. Another curious case is Deed of Valor as one of the few buffs that applies a penalty to the user, it is also a full uptime skill but limited to 2 min as a possible way to secure the user, yet Pre-emptive Strike has also a consistent issue and is a toggle.
Since they removed the only two skills that allowed self buffs to be shared this design lost its meaning, it’s nothing else than a way to burn skill points for passive effects in an occasional SP drain, these full uptime will be maxed in the majority of cases for their sheer power.
The big irony is that buffs the other self buffs that offer power spikes, turning you super saiyan for few seconds, may be perceived as not as reliable since they have, in most cases, a cast time shortening duration and hindering stacking buffs. It is bothersome to not have that power constantly but it makes skill points be valuable as an active component rather than a semi-permanent passive.
Before getting in the discussion ‘should full uptime buffs have longer duration’ it is better to ask if the way how buffs are handled in game should be changed or not, after all spending points on party buffs is a real deal since it enables that power to be used by classes and/or characters that don’t have it available.