Soil pipe connections through wall underground

[tvrulesme]

Planning drainage for a new bathroom. Assuming that all the falls/gradients are correct is there anything wrong with this plan? Soil pipe from toilet goes through wall below the floor level so that I can connect a shower waste (wetroom so flush with floor). On the other side of the exterior wall is the soil pipe vent (with rodding access) and an inspection chamber where it joins the underground drain pipe at a 90 degree angle.

Been through all the regulations I can find and seems ok but maybe I am missing something? Does the shower trap adequately stop the stench from the WC waste or is there a key component I'm issing?