And all this work to find out what the approach speed should be and adjust it for weight.
There is a very easy way of SEEING if your at the right speed.
Just look out the window and set the attitude. Your wanting to fly the approach at AoAcrit minus a safety margin that margin won't change so if you set the attitude you will always be at the right speed. Then adjust the power to maintain the decent profile that you want.
To be honest the picture doesn't change whatever type you fly. On a new type ask the instructor to demo a approach and check that its the same then carry on and do the same as you have always done.
Sometimes I think this industry fixation on airspeeds causes more problems that it solves in teaching.
It is more than possible to fly an aircraft with no flight instruments what's so ever. I spent 900 hours in the RHS of a tommy with no instruments. And could spot the approach speed being wrong looking at the wing tip.
Learn your attitudes for each stage of flight and set them, hold them and trim for them. Then let the plane do the flying.