Drawing on the wall

I’m a beginner and just started the LOD programme. I don’t currently have space for a sturdy easel. My current solution is a large piece of grey board Velcro’d to the wall with my drawing paper attached to that with Blu-tac. It feels very comfortable to work standing here for at least a couple of hours - much more so than at a table. Obviously I can’t adjust the wall position in relation to a subject but the exercises and replications should work? How far can I get through the programme without an easel?