Koji should have it. It will be the same as vs the 3rd Raikage when Naruto used its advanced reaction and sensing abilities and when Madara used it vs Tobirama when Madara used the advanced reaction and sensing abilities. It effectively negates the biggest advantage of FTG which is the instant surprise attack.
So? He doesn't have any frog features(nose, teeth all jagged, feet). His eyes and markings are different than Naruto's and sure they match Jiraiya's but thats where his and Jiraiyas Sage Modes stop sharing similarities because Jiraiyas is not quite perfect. But like Seelentau said before that means nothing basically. Koji lacks the Frog features meaning that he is a "perfect Sage".
Naruto lacked Frog features before he became a perfect Sage as well when he was training on Mount Myoboku. Just lacking frog features isn't exactly an indication to me since we already have an example of a perfect Frog Sage in Naruto. And Naruto himself had rings around his eyes with no frog features as well, but still was imperfect at the time.
In any case, while Sage Mode did help Madara react to Tobirama, Madara himself was at a higher level than pretty much everyone in the series as well. He was at peak of his life physically on top of having Hashi cells while retaining all the experience he gained well into even the Third's reign, with Sage Mode as an even bigger bonus. So just because Madara managed it doesn't mean Koji would.
Between the two I lean towards Tobirama because I'd bet on Tobirama if it were versus Jiraiya, and I haven't seen that much to definitively place Koji above him. Though if Koji were substantially stronger than Jiraiya then I could definitely see Koji winning
Koji is definitely stronger than Jiraiya. He is a clone who is modified by scientific ninja tools, most likely a perfect sage. He has fire style jutsus similar in power to Tobirama's water style. I think it's safe to assume he is more powerful than Jiraiya as he forced Isshiki to use the 2nd level of his dharma wheel dojutsu. Tobirama is still so freaking powerful that I personally think this fight would result in a stalemate or death for both of them.