so it seems that when you infuse a weapon with a spell it is not activated unless you swing the weapon with an attack/ambush/normal mstrike. when you beseech your weapon and try a grapple/punch/jab with a cestus or other UAC compatible weapon, the spell will not flare.

Also some spells are broken when infused, like 118 for instance. when you mstrike after beseeching or attack the target using "attack" or "kill" the web spell is cast as the CS version against a single target. if you ambush, it is cast as an area web. (using normal weapons, not UAC commands.)