To follow up on what Ellen wrote, if, as a habit, you check your "Requests" list weekly, you can automate this process:
* For all of the trusted list requests you sent a week ago, check them to see if they have been granted or not. If so, great. If not, go to the profile and post a message to the PM and also put a comment on their profile that you've requested access to said profile and include a link and a smiley :-) and a "thanks!"
* For all trusted list requests you sent two weeks ago, assuming you emailed the PM last week, check to see if you've been added. If you have, great, if not, maybe it is time to file an unresponsive PM request. Sometimes PMs miss your request, your post, and your comment. But, when they get an official notice from Wikitree, they usually act and you get added.
It is a bit of work at first, but if you start doing it as a regular weekly chore, you'll get faster at it and I find that it doesn't take but 5 or 10 minutes each week. And then, over time, you'll be on 100% of the trusted lists you requested - usually by being added, or occasionally by adopting the newly orphaned profile if the PM has gone missing.