Jasper,
Before I had the proper equipment I used my coffee table, a foot stool, a chair, and I never once had a problem. I think you'll be fine, especially in L&G where the weight is light, PLB will be heavier, so try it out and use your discretion. Just clear a spot around the chair so you won't hit anything if you fall, of course at 6 feet, that's quite a spot:7
Mattea