The spell checker does not have any filtering for obvious meta tokens, such as the contents of \usepackage commands. In the following snippet, I see 14 spellcheck markings. This would be very easy to filter out, since all latex documents have \usepackage commands, and we always know for certain that they are not to be spell checked. 

\documentclass[a4paper,10pt]{article}
\usepackage[utf8]{inputenc}
\usepackage{amssymb,amsmath}
\usepackage[left=0.5in,top=0.5in,right=0.5in,bottom=1in,footskip=0.25in]{geometry}
\usepackage{qtree}
\usepackage{multicol}

Reproducible: Always

Steps to Reproduce:
1. Open any latex document
2. Enable "Automatic Spell Checking"
Actual Results:  
Tokens in the standard commands are marked as potentially misspelled. 

Expected Results:  
Tokens in standard commands are never marked as potentially misspelled, because they will certainly never be found in the dictionary. We never have any spelling constraints of any kind for these tokens.