Machine rebuild time - options...

[m_c]

Jonathan, do you ever think that you overthink things too much?

If you're using a wider disc, feedrate isn't going to be the same. You could try and make it the same, but you'll need far more force than a multiple of the disc width difference, which then results in the disc wearing away quicker than it would normally (or clogging if you really push it), and most likely overheating the grinder.
Plus using a proper grinding disc for grinding puts far higher loads on a grinder than cutting, and if you're wearing grinders out, you're either doing something majorly wrong, or you want to buy better ones.

[Jonathan]

Jonathan, do you ever think that you overthink things too much?

I probably just did yes, but not having used one much myself I can only really judge from theory and finding sources.

feedrate isn't going to be the same. You could try and make it the same, but you'll need far more force than

Of course...So it depends on which the limiting factor is - the force / wear on the grinder or the power output for given duty cycle.

I'll leave it at that as I fear I'm going a bit off topic.