Halliday & Matthiessen (2014: 527-8, 527n):
As with those that are projected verbally, so with those that are projected mentally the exact limits are fuzzy; they merge with causatives and with various aspectual categories. The relevant criteria are similar to those set up for propositions, except that we cannot realistically test for quoting, since mental proposals are rarely quoted.* For reporting, however, if the process in the dominant clause is one of desire, and the dependent clause is a future declarative, or could be replaced by a future declarative, then the structure can be interpreted as a projection; for example we hope you will not forget. In Chapter 8, Section 8.8, we shall suggest an alternative interpretation for those where the dependent clause is non-finite and its Subject is presupposed from the dominant clause, e.g. he wanted to go home (where it is difficult to find a closely equivalent finite form); but there will always be a certain amount of arbitrariness about where the line is drawn.
* Note that ‘I wish he’d go away,’ thought Mary is a quoted proposition incorporating a reported proposal, not a quoted proposal, which would be ‘Let him go away!’ wished Mary. As with mental propositions, so also with mental proposals: the notion behind quoting is generally that of ‘saying to oneself’, or saying silently to a deity as in prayer.