incremental attribute modifiers

hello! i'm working on a wave-based minigame that allows the player to choose upgrades between waves. right now i have code that will apply an attribute to the player if it has the right item, but i want these upgrades to be stackable. is there any way to do this with the function below? execute as @a store result score @s dogarena.shop.upgrade.speed run clear @s *[custom_data={dogarena.upgrade.speed:1}] execute as @a[scores={dogarena.shop.upgrade.speed=1}] run attribute @s minecraft:generic.movement_speed modifier add dogarena:speed 0.01 add_value execute as @a[scores={dogarena.shop.upgrade.speed=1}] run scoreboard players set @s dogarena.shop.upgrade.speed 0 thanks very much for your time!