The only problem is that the RTFM key is the only hidden one in the registry. It can be murder just finding whether it exists, and getting it's value, both of which you have to do by indirect means, by assessing the performace of other devices, processes and accessory apurtenances.
Then, it can only be manipulated by processing, external to the computer, through a separate RTFM utility, and applying the results of the external processing to other aspects of the actual application and its installation - with the blind hope that the value of the hidden key will be suitably affected. Sometimes it can't be changed.
The more deeply buried RPOTFM and RMOTFM keys can be even more troublesome, since either of these may turn on arcane processes you'd never expect to see.