I searched for loadMissingCount in issues, the discussion board and Google. I only found a Tweet: https://mobile.twitter.com/gdebrauwer/status/1427294207429992452

load() has loadMissing(). If there is a functionality to only load relationships if not already present, I think it would be just fair to provide the same possibility for relationship aggregates (lazy loading relationship counts if missing etc). Use cases should also be similar to the ones loadMissing() has I guess.

I'm personally looking for it because my application makes use of service classes. One issue I see with that is possibly creating a load of database queries throughout the process in some scenarios.

Assuming I have a method like this:

    /**
     * Retrieve the amount of affiliates the advertiser has.
     *
     * @return int
     */
    public function getAffiliateCount(): int
    {
        return $this->user->activatedAffiliates()->count();
    }

Prepending the main line with a loadMissingCount() is what I am looking to do.
This would allow me to not run into an issue with one single user being processed like this as I don't have to worry about the count being eager loaded, but also enables me to eager load the relationship in previous steps for a collection of users and have them being passed over to the method one by one, let it do it's thing (and possibly more, this is a simplified example) and not load the count another time.

Update: This is similar to what I am looking for, but just having the method above would be much more elegant and have the same data attribute naming convention with the underscore as it would with have with regular eager loading in the first place.