we need a setting for oil the same as for ores, so that we can turn on/off infinite resources

In next version setting "Infinite resource spawn chance" can be = 0, to turn off infinite resource spawn completely.
But resource patches doesn't have as much amount as normally and it doesn't scale with distance, so you'll need them.
If you have too much resource income with infinite resources, you can always increase "Infinite resource mining time multiplier" in settings.

I mean, so that there would be an option to turn on infinite oil like in the original game

It should be somewhat close to original settings - while you haven't depleted it, you have high oil income, afterwards you'll have infinite oil leftovers with slower mining. By default mod settings infinite resources have 500% mining time, so it's the same as original 20% lower yield limit on oil.

thx