1) Enter 1 or more "User defined online services" and mark the "Include in managed profile switcher". I did this, for example, with the new Timetravel blockmasters.co:3555
2) Click on any profile and "Edit profit profile", edit something and click "OK".
3) Now your freshly made User defined online service is not visible in "View details -> Profit switching" and is also not visible in the online services tab. So the profit switcher will ignore it.
4a) To activate, you have to go back to "User defined online service", click the service, demark "Include in managed profile switcher" and hit "OK"+"OK".
4b) Back again to "User defined online service", click the service, now mark "Include in managed profile switcher" and hit "OK"+"OK".
Profit switching will work now until you edit something again in any profile. So you have to repeat 4a and 4b again to activate the profit switching again.
If you have more than one User defined online service, you have to demark all of them and also mark all of them whenever you edit some profiles.
EDIT: They are also not visible in benchmark until you done 4a and 4b.
I went ahead and disabled the MultiPool.us integration in Awesome Miner as their API has been down for a while now, and now the Blockmasters Timetravel entry shows up in a few seconds after adding it.