Any good tips out there to stabilise a telescope on garden decking?

We only have a small garden that is decked in all locations a tripod could be rigged.

When we try to align the tripod it is very clear that our movement around the telescope is making very slight shifts in the line-up resulting in very slightly blurred go-to movement on long exposures - making imaging DSOs near impossible.

Has anyone found a good way to mitigate this movement? I did think about getting some pathing slabs, but this makes it impossible for my son to then setup the scope on his own (and where would I store them!?).