Ryan marked his 25th birthday with the announcement of the two-year contract extension which sees him stay at Hull College Craven Park until the end of 2023.
He moved up to Super League last season after joining from Bradford Bulls where he had been a prolific try-scorer.
Although the Halifax-born player has yet to fully secure a regular starting berth with the Robins with competition from the likes of England winger Ryan Hall and Ben Crooks, he has impressed when called upon and recently regained his place in the side.
“Ethan has shown that he is a young guy developing and doing very well,” said Smith.
“He’s applied himself as we hoped and wished and has shown us that he could be a really important part of our future.
“He has developed his body enormously by putting on weight, size, strength and speed. That is one of his big attributes, his speed, but he is keen to learn and he has learnt a whole lot since he has been here.”
Ryan is the latest player to commit his future to the East Yorkshire club after Jordan Abdull announced his new deal this week with hooker Jez Litten also recently re-signing.
He scored three tries in six appearances last term and scored on his first appearance of this campaign against Castleford Tigers.
Smith added: “Ethan’s done a terrific job.
“He had some great experience last year, but he got hampered by an injury or two which is part and parcel of rugby league.
“But on the whole, he’s been able to overcome those obstacles and he has got the capabilities to compete at Super League and do it well.
“I still think that his best is yet to come, and he does as well, and that is part of why we feel that in the next two years he will grow and become a big part of our future and our success.
“It’s all about identifying those young people with ambition and he certainly is one of those that has. I think he can go a long way in the game.
“There’s competition for places and he’s certainly one of those competitors at the moment. He gives me a pleasant headache in the terms of he is a great option to have and one that has kept a couple of the more experienced boys at bay.
“He is a delight to work with and right from the word go he has asked questions, he comes and sits in the office and does a lot of work with Dave Hodgson and they go through a whole lot of winger play.
“He is hungry for knowledge and eager to keep on impressing. He’s got a great attitude and we are delighted that he has seen the ambition of the club and got his own ambitions to be successful as well. They all tie in nicely for our own plans.”