Be as generous as possible. Sharp corners are difficult to extrude and provide stress risers. The tighter they are, the more expensive the extrusion. Indicate the truly important dimensions. Show how the part will be used.
Some materials are easier to extrude than others.
Some are more forgiving when design rules are broken. Some will accept a heavier loading of a reinforcement or filler than others. Materials selection is the single most important factor in design success, precision production and scrap rate. Contact us for our recommendation. In the meantime, provide for disassembly and materials recovery.