I started getting serious with gaining weight since Mid July. Had some unknown weight gainer for 2 weeks and it was crap. Then I learnt about calorie deficit. I was 47/48KG at 175cm. That's my weight prolly for the whole secondary life. After googling up some tips, I bought Horley's weigh gainers. Drank w/ full milk 3 times a day and eating 2600 - 3000cal per day. But after more googling I found out that it ain't enough. So I started working out by lifting weights.

It has been two months or so and I've gained 9KG. Still borderline skinny though. I wanna be optimistic and gain a few more till it's proportional to my height without being too drastic. My main agenda is to look good in clothes and having a better posture.

If you wanna do that way then go ahead.
My calorie counts are rough but it should be within the same range. I use the myfitness app to have my rough estimates.

I just think of my supplements as a backup and after workout drink. There are those days where I just don't get to eat the right foods. But I do think lifting weights helps me gain weight a lot faster than just by eating. As you'd know, muscle mass is heavier than fat. I do feel better to work them muscles. It shows better too. 

Since I'm still a student, I had to cut down on supplement for now. Compensate by eating more carbs and protein. I still drink milk. Supper is a must for me, be it a simple shake or some crackers or noodle.

So to answer your question, no. Just stick to right foods. Albeit you lift weight to reduce drastic weight loss.