Does it matter what undercoat you use?

Yes, it matters what undercoat you use, as different undercoats or primers are formulated for specific surfaces and problems, and using wrong type can cause poor adhesion, bleed through, and premature failure. For example, wood needs wood primer or oil based primer to seal tannins and knots, otherwise tannins bleed through latex primer. Drywall needs drywall primer or PVA primer to seal paper and mud. Metal needs metal primer or rust inhibiting primer to prevent rust, regular wall primer will not prevent rust. For glossy surfaces, you need bonding primer to grip slick surface. For stains, smoke, or water marks, you need stain blocking primer like shellac based primer, otherwise stains bleed through. For car underbody, rubberized undercoat is for rust protection, while wax based is for cavity protection. For masonry, masonry primer is needed. Using interior primer exterior will fail due to lack of weather resistance. Also oil based versus water based matters, oil based seals better for wood but has fumes. So yes, it matters greatly, you should choose undercoat labeled for your surface, such as wood primer for bare wood, drywall primer for drywall, metal primer for metal, stain blocking for stains, and exterior primer for exterior. Matching undercoat to surface ensures adhesion, sealing, and long life.