Dont cut anything. Go buy a piece of 1 inch thick oak (by 1 inch wide), wrap it in white vinyl and put it between your seat and your engine hatch. Put 2 screws into it - more than likely the top of your seat already has wood there anyway. The slight angle will never get noticed. The 1 inch strip will never get recognized.

Or you can unbolt the backrest and move it up so the pad doesnt come down as far.

or if the underside is just a plastic insert use a heat gun on the area and close the hatch to make a imprint..i like the spacer idea better..

I would use a plunge router with a template. Make perfect plunge cuts then gel coat them back up.

are the current hoses 90s or they curve back? Hard to see from the pic, but could you just get a 90 fitting and make it turn? Or like Keith said, put a spacer, but the 1" might not give you 1" clearance as its closer to the hinges.

Just a thought here...... If there is room. Crawl in with the engines and have some one shut the hatch for you. Look at the hoses with a flashlight , and feel them with your fingers ( If you can ) . The might only be touching the Hatch when the hoses are warm , and expanded slightly from the hot water and pressure . That wouldn't be much of a problem. The spacer idea would be the cleanest and easiest to me.