There are no advantages of Bamber leaving the silencer by Sheila. But several disadvantages.
It's a good job he didn't as it had paint, blood & Nevill's hair on.
Both supporters & guilters agree his best option was to put it back in the gun cupboard. Just prior to & a few feet from where he was going to burn Nevill's back.
Even Bamber says the back burns were inflicted minus silencer.