What proportion of casts should be heals?

[AnotherPerson]

ideally you want it to be roughly 50/50

that is, min ilvl and new folks, you heal about 60% of your buttons and dps 40% as you get more experienced, ilvl boosts, mechanics learnt etc, it would graduate more to 40:60

whats important is that it is fun and you have a variable and significant enough portion of your kit be not healing, ie dps, support, buffing etc

Is that supposed to be the ideal? With no deaths, 100% proper rotation, and 100% full understanding of the mechanics?
Because things vary greatly when people do stuff for the first time.

I don't think this is viable because a player's skill level affects that healing % a lot more than up to 20% currently. For the change to be 20%, the outgoing damage must happen frequently enough to reduce DPS time, but it also means dying will skew that bar a lot more on healers. It's more like a 80-90% heal / 10-20 % DPS if you were forced to continuously heal that much to keep 60% healing uptime due to the way deaths work. The 25% stat penalty is no joke, especially on healers, doubly so if they die twice.