Thanks for everyone's advice on the matter.
On Saturday the T decided it was time to reveal itself. Got home and the closing was opened up. The molt has been incorporated into the webbing so no sexing unfortunately, but it is jet black with the orange Nike signs now clear. It went from about 6.5cm to roughly 9cm.
I suppose what I have learnt is too rather leave them be which will be tested soon seeing as my 9cm Avicularia avicularia has now closed itself off whistle2