It's all good, yeah I've bulked for a few months on keto before, to be honest, I prefer carbs for bulking - but more for the flavor and less for the benefits. Keto is probably a more efficient bulk, but the carbs on a traditional bulk can be delicious and a nice mental break.

If you're a hard-gainer, I would tell you to just eat more calorie dense foods - avocados, nuts, cheese, pasta, etc. Something that you can eat loads of and still enjoy. Maybe even add some dessert to the end of each meal.