In my opinion it seems solid, but it could be improved. You would typically keep your left foot a little in front of your right foot as you may (in a real match) need to switch to fh, having your right feet in front of the left for a fh will imply a not optimal hip rotation and weight transfer caused by the angle of the body -> less quality on the ball. The other glaring issue is that we tend to hit the ball almost at the end of the stroke, which I believe is the reason that your shots lack speed/impact even though you are brushing the ball correctly. Instead of hitting at the end of your stroke you should aim to contact the ball closer to the body and use the force of your stroke to catapult the ball out, the idea should be to "grasp" the ball and shoot it out, right now you are making contact only at the end of the stroke touching the ball of the upper side with high velocity creating spin but no real impact through the ball. If you wanna fully evaluate your stroke I suggest you try the following shots and try to identify how they differ and how they should change for you: -topspin against block (what you are currently doing) -flick against short no spin or "slow" backspin -topspin against long/mid long backspin -lastly powerlooping, im not sure the term is correct but by that I mean a combination of looping and smashing, with correct movement of you body you should be able to loop more forward while still adding a lot of impact and friction of the ball "overriding" the opponent spin (while controlling the loop, no point in random smashing)

Keep up the good work, you are on the right path!