This will serve you better. Glen will concur, he now stretches the corners on the ends first.
The side stretch will feel a bit light, and the temptation to go more there than the ends should be resisted with Simonis. Unlike some cloths, it stretches the same in both directions, and you want it to be balanced. You know you have the right index when your end pulls are needing some muscle.
Another nice tip on a table with deep side pocket cuts is to close off your side pockets before you pull the ends. I find I can get away with a little less slack this way. Watch the grain in front of the pocket closely and pull it straight when you do this.