The methods in the deck and on the lists are only meant as a source of inspiration. Do not let yourself be limited by it. There are so many more possibilities!
Except for thinking about the methods, it could also be useful to think about what the result will look like. How are you going to present the information so you can pass it on to the next step in the process? Is it a list of demands? A prototype? A table comparing the features of various solutions?
For a good approach, also consider the following two questions: Do you really need all these research activities to arrive at a good end result? And is this design feasible within the time available to you?
About feasibility: How much time an activity will take does not only depend on the method itself, but also on how you are going to do it. If you interview two people, that takes less time than interviewing ten. So also think a little about what you would like to do exactly within a particular activity.
There are also other methods for determining your approach that would be interesting to use in combination with the DOT framework, such as making a product breakdown structure and a work breakdown structure.