I use emacs for most of my daily development, but always rely on nano or vi in the terminal due to emacs startup time. I'm going to give mg a shot this week!
2. Emacs daemon - as many suggest, why would you ever quit emacs?
But if you do find you shut Emacs down...
3. Slimmed down alternative init eg. https://github.com/ocodo/.emacs.d/blob/master/emacsq & https://github.com/ocodo/.emacs.d/blob/master/emacsq.el (note this init could be even slimmer, but the start time is about 2.5 seconds, which is fast enough, and I get a very well configured environment)
Or just ...
4. emacs -Q - no init.
One of these are going to solve your issue, without having to interrupt your emacs flow.
You could also look at your init for bottlenecks and have a secondary script. Which you can optionally run when you want those features. Keep the real init minimal.
There's many strategies.
Only annoying thing is the way it retains buffers for modified files when you exit, even if you choose not to save them.
emacs -q (or faster, -Q) could be used in a pinch, but I find default emacs almost unusable.