No, because your clearances are set with the valves closed. Any slop in the timing chain would delay opening, but not increase it. You might be a bit hypersensitive, having just adjusted them. Or... the locknut on your adjusting screw may have loosened, and your clearance is growing (sorry!). That stuff is all hardened steel and takes a long time to mushroom, but it may be worth popping the covers off and taking a look.  Too loose is better than too tight. Some motors tighten up over time; I don't know about this one though. VWs were famous for it. 8)