I understand the reasoning behind why spore spread was removed when death on tick damage, as it led to a situation where a single spore cast could slaughter wave after wave without touching the keyboard/controller once the spores got going. Now, you have situation where it's a struggle to keep the spores popping as the counter rises, and saryn's gameplay becomes racing around recasting her 1 to maintain the damage counter. This adjustment was effective in creating a steady-state equilibrium for the damage counter--which is truly necessary to prevent her kit in overshadowing her teammates--but the gameplay becomes monotonous and generally ineffective (reminds me a lot of Ash's bladestorm rework, and sadly I have barely touched him since due to the frustrating and burdensome mark mechanic overshadowing him as a frame). It feels bad to see teammates slaughter enemies before you can infect them spores.
I would hugely prefer to bring back the spread on tick damage, but add in a penalty to the damage counter for every time that this happens. That would incentive players to remain active, as the more enemies that they kill themselves will produce a higher spore damage counter over time, spending more time shooting, working with teammates, etc and less time spamming 1.