Have to agree that chip grafting allows for my my 7 thumbs dexterity and “finesse” and would appear beat approach for a newbie. Only multi flora “roses” l have are the tender hybrida, lykkefund and ydrerosen, plus bloomless Geschwind. Though gives me idea to try the hybrida as surrogate. Also pickering rootstock but most buried (graft) to make it through winter. The grating of hardy on tender may seem odd but at end of the season it would have protection placed.