dafranca, LOT theory would suggest that you will not gain as much as others from pulling the ligs but you still may gain some. Try mixing in some BTC stretches for a month to see if you can pull those ligs a bit.
Yeah any v-stretch variant like the a-stretch will put good strain on the tunica if you are doing good long stretches. If you can’t keep the stretches held at good tension for some time then try modifying what you do.
I found that an inverted v-stretch over a can placed between the legs worked well because I could lock my arm straight and use the body to power the stretch rather than the arm. If you do a good warmup and then stretch for long periods (3-5 minutes) you will probably make good impact on the tunica. An alternative might be stretching over a baseball bat positioned across the thighs.
Rest for long enough to regain the circulation. You can aid this by doing a couple of jelqing movements or slapping the penis against the thigh.
When stretching always ease into the stretch and pull to the maximum then ease of a tad. Often kegeling and releasing a couple of times will allow you to exert more strain. Go by feel and if you pull a stretch that doesn’t seem to be having an effect stop and restart.
Hope that helps.