When I didn't have a LA I would tie my T-shirt quilts. One tie every 3". It did not detract from the T-shirts at all. Now I usually do an E2E on them. I am not aware of any batting on the market that allows for no quilting as far apart as your shirt blocks are large. The largest space I know of is 10" which is some quilters Dream products and Warm and Natural. You will need to do something other than a bar tack in each corner.