Buffer/grinder speed control

Was not sure if this should go to general discussion or here; figured more relevant to abrasive tech.

My question is about angle grinders/buffers and speed control in DIY environment.
I just bought maketa angle grinder with adaptive speed control, but no manual speed adjustment. Makita XAG04Z 18V LXT Lithium-Ion Brushless Cordless 4-1/2” / 5" Cut-Off/Angle Grinder. There is a more expansive version that allows manual speed control and an allot more expansive buffer. What process steps in grinding / polishing / buffing will I not be able to do without manual speed control? I realize that the real maketa "buffer" has different ergonomics which make it easier to use on daily basis, I don't care about ergonomics or daily use. Not trying to compare the two tools; rather trying to determine what process limitations the cheap grinder I bought would present me with. Just off top of my head i'd think the 8KHz wheel on my cheap grinder would make it hard or impossible to use liquid polishing pastes, but is it a big deal, or can i just use wax/soap based pastes and get same result?

Most of my buffing and polishing will be on metal, not of car paint jobs, any gotchas on that front as far as speed control goes?

Thanks ahead

no limitations on metal, you'll be fine everywhere.

On plastic too fast.
On tile/granite too fast.

I am redoing my bathroom right now, and had to polish some granite. The polishing pads are low speed. I took a sander/buffer and made a 5/8 11 adapter for it. Because my grinder was losing too much torque by turning it down with a speed controller.

Normal tile/granite grinders are low speed with water feed.

Lower speed is pretty essential for something like buffing a car or you absolutely will just sling off most of the compound. I have a Makita variable speed buffer made for automotive work and it has a lot more torque at low speed than something like a slowed down angle grinder, so you can get a lot more work done if you need to apply pressure.

Thanks all. Sounds like it will work just fine for 99% of what I need. Also, sounds like the things it can't do, the variable speed model may not be able to do well either (depends how they achieve the variable speed). So it sounds like for the things that this grinder can't do I just need an actual dedicated buffer rather than a more expansive grinder.