In that case I would say that adding a frame is something appreciated in Instagram. But beware, there are pros and cons!
Pros:
– Who takes a look at your profile will see something much more balanced, with more space between the images, and could appreciate your entire work better, at least at a first glance, focusing more on the pictures because they are framed and separated from each other.
Cons:
– It may be annoying for the people who follow you to see on their feed your pictures with a frame. There it’s a different contex, where they are used to see big pictures, and they may skip a little bit smaller image just because they are not used to it.
At the end, I think that an Instagram profile without frames becomes a pure mess, with colors smashed next to each other (unless you don’t pay attention to the juxtaposition of every single photo you post, which is something really complicated but really stylish indeed). You have the downside of smaller images, but I don’t think that’s a big problem. I think it can force people to check your website, if you have, to have a look at bigger and better organized pictures. Frames are definitely a good idea, you just need to find a style that you like and suits your kind of photography.
My two cents.