Quote - Is it possible to obtain HDR images that are even sharper?...really crisp?...

You have never mentioned what size map you are using, so it would be hard to say.

Keep in mind that the Envsphere is about 225 m in radius, making circumference 1400 m.

If your map is 1024 wide, then you only have 1 pixel about every meter.

FOV on 35 mm camera is about 54 degrees, so the amount of sphere you see in viewport is 1/7 of total.  For 4096 pixel wide, you are only seeing 600 pixels or less.

HDR images come in all sizes, you just have to figure what size suits your needs