These models are based on the Gridifinity system and should fit together with any other block, and also stackable.
More info about Gridfinity here: https://gridfinity.xyz/
Well whats a desk without a cigar ashtray, and how will you ever survive without a cigar after coffee and breakfast ?
PETG could be used,the ashes will not destroy the plastic, however if you drop a glowing cigar in the tray it will leave a mark... so perhaps a more heat resilient filament is optimal :-)