I've participated in (and facilitated) ideation workshops. being event-based, they sometimes take quite a bit of time to set up, especially in bigger companies and teams. While they are great for brainstorming new out of the box ideas, I find that ideas often come at the most unexpected of times. My question is, does design thinking offer a solution for ideation that's not event-based. more of an evergreen solution or platform where members can post their ideas related to a particular problem statement over a longer time window than a single event.
I think there are many crowdsourcing platforms that apply this type of concept that already exist, especially for connecting people with ideas with people that can bring those ideas to life. I won't put any links but if you search for the keywords 'crowdsourcing' and 'invention' or 'ideas' you'll see many platforms that implement some or all of the design thinking process and methodology.
Having said that, the idea of hackathons and design sprints is to get to an outcome quickly and test ideas when it has traction, so if you are thinking about an 'evergreen' alternative then it is more likely that you are looking at problems that are going to exist for a long time or always need to be solved (e.g. innovation or optimization).
In terms of your question, design thinking is just a set of principles and concepts that can be implemented in a number of ways, and you can tweak the variables and elements to suit your particular need. I have seen how the double diamond popularized by the Design Council evolve into the triple diamond popularized by Zendesk, and even a quadruple diamond design process discussed.
In any case, because design thinking involves an iterative process, the length of the iteration can be extended or reduced as required.