E.acrurensis is an invalid name. What you have may be the triagonal form of euphorbia ingens or a weird form of euphorbia trigona.

I dont see anything wrong with the plant, so keep doing whatever you were doing.

Further to what Stefan wrote, I think you're doing a fine job. If you can, vacuum off the webs (they look like traditional cobwebs/pet hair things that can appear in winter). Your watering sounds fine. Corking is considered normal in many cactoid Euphorbia species, so as long as it's not mushy I shouldn't worry. If the etiolated growth doesn't tickle your fancy, take it off - the plant won't suffer certainly, and many believe it's better for the health of the plant. Careful of the sap, too, so keep some lukewarm water nearby to staunch the flow of the white latex (which can be an irritant or much, much, much more worse, depending on your sensitivity, so keep it away from skin / all mucous membranes).

Stefan, just a question on your description - there's a triangular form of E. ingens? That would be something to see.

Euphorbia ingens is pretty variable. They look a lot different if you grow them from seed.

They can have from 4 to 6 ribs, as an average, and look quite jagged when young. Some even have those patterns...

I got 3 seedlings, and one of them still has 3 ribs.

And they were sown roughly at the same time.

https://garden.org/plants/photo/207727/

This would be the form with 5 or 6 ribs.Norm is 4.

This is the plant in this topic:https://image.shutterstock.com/z/stock-photo-cactus-tree-candelabra-tree-euphorbia-ingens-1113070103.jpg