Advice on adding workout class into 5/3/1

I've been doing 5/3/1 in various formats for over a year now and really like it, generally I do 4 days/week, 4 week cycle. Depending on the week I will add either a stretching/mobility/long casual run day or 2, depending on work and family.

I want to start a one day a week hour long strength/ endurance workout class taught by a good friend, generally its a mix of medicine balls, kettlebells, bodyweight, row machine, etc. Its a pretty strenuous class and I want to push myself, however I think the class could affect my 5/3/1 workouts, especially if I can't schedule in a rest day after.

Question: should add the workout class as a 5th day or go to 3 days a week 5/3/1 and make the class my 4th scheduled workout of the week? Or should I add it to the back end of one of my 5/3/1 days, maybe replace my deadlift accessory exercises with the class?