You absolutely need to sign ALL trust cheques yourself.....
I do more than 800 deals a year and I am not too busy to sign my own cheques. You can manage high volume closing days in advance. Once you have the SOA, I suggest you print out the cheques (you can set up easy ways to print out cheques using Quickbooks or something), and organize closing packages before you even get funds. This way once you are in funds, you can get the runner/courier to go immediately.
Unless you are in a smaller centre, I don't see why you need to write multiple cheques for purchase transactions. In the GTA, most Lawyers accept direct deposit or wire. Further if you are on FCT's easyfund/payout platform, you get to do transfers without using certified cheques.
For sales, we almost exclusively use FCT's payout platform, you don't have to leave the office or do any cheques. FCT help you payout the mortgages and directly deposit to your client's account.