Ale fermented with lager yeast at 70F

What happens if I ferment this beer: https://www.brewtoad.com/recipes/cc23-elysium-summer-ale

with the fermentis lager yeast at 65F-70F?

Will the lager yeast produce a lot of off flavours at high temp?
I think steam beer by anchor is produced like this, right? Pale ale malt fermented with lager yeast.

You can go a degree or two over the max ferment temp for lager, depending on the yeast, for a steam beer style brew. Any more and it'll just kick out loads of awful fusels. Fermentis seem think their lager yeasts can handle up to 71f but ideally up to 59f. I wouldn't believe it personally and would opt for a fermentation around 60f if that's what you want to do.

Prefer to just chuck nottingham or us-05 in myself.

Plenty of lager yeasts will taste fine at normal to cool ale temperatures, but I don't know of any that will make good beer at 70, which is on the high side for most non-belgian ales.