SLDL's, like regular DL's, stretch and call upon the lats to assist in the exercise. So, yes, the lats do get their share of work, and usually with a fairly good pump. Most always, any form of DL's will affect the lat's/back greatly.
Might try doing GoodMornings (keeping the lower back flat) with the toes on a 2X4, plates, etc. Don't need any where near a heavy weigh in this movement. Exceptional stretch.
Usually a good idea to work the hams curls one leg at a time. Suggest the standing leg curl machine or similar devices, over the lying versions. Even the sitting position ham curls can be very rewarding. .
One of the better ways to insure constant focus and work on the hams, both positive and negative reps, is to have training partner resist the curling motion. Usually a strap around the ankles is used, but hand resistence can also be applied. Track athletes use this a lot. You should be receiving 100% effort throughout the exercise. Usually best preformed on a higher bench/table.
Can also assume the kneeling position and have the training partner hold the asnkles/feet down, while you lower the body and come back up again. Something like Montague suggest. Hold a BB plate as you advance in this exercise. Good luck.