I thought LN used Joe Gibbs Racing's DT40 oil? They also have a break-in oil that is recommended as a flush before switching from Mobil1 to their DT40. Definitely check with the mechanic who did the work. You don't want to void any warranties.
https://www.summitracing.com/search/product-line/joe-gibbs-driven-br-break-in-motor-oil