My attempt at a queue system for event callbacks.

QueueSystem.lua

type QueueKey = {
    RBXScriptSignal,
    (...)
}

local arguments = { [QueueKey]: {any}? } 
local connections: { [QueueKey]: RBXScriptConnection } = {}
local queues: { [QueueKey]: number } = {}


local function startQueue(key: QueueKey, event: RBXScriptSignal, callback: (...), delay: number): nil
    queues[key] = 1

    while queues[key] > 0 do
        callback()
        task.wait(delay)
    end
end


local function threshold(limit: number, event: RBXScriptSignal, callback: (...), delay: number?): RBXScriptConnection
    delay = delay or 1/30
    local count = 0
    -- i have no idea if this will actually work lol
    local key: QueueKey = {
        event,
        callback
    }
    local queueFound: number = queues[key]

    if queueFound then
        queueFound += 1

        return connections[key]
    end

    task.spawn(startQueue, key, event, callback)

    return event:Connect(function(...)
        if limit == count then waitSomehowLOL() end

        count += 1

        callback(...)

        count -= 1
    end)
end