X15 pto regen issues

[Oilfield238]

Looking for any sort of advise for 3 new trucks. 23 peterbilts with x15s. Oilfield trucks that sit on location for weeks on end in pto mode at 850rpm 24/7. They drive a generator via pto to charge batteries for electric drawworks. They can be plugged into 480 3 phase and run solely off that but shore power is not always available. They also have onboard generators that can be used to run draworks with the x15 off but we’ve been having issues with those so we’ve been having to rely on the x15 in pto mode to run the generator. Manufacturer says we cannot run trucks over 900rpms due too pto ratio and generator. They work fine in the summer. Once winter strikes and we’re below 20° all the way to -40 they will not regen. Pto mode regen is enabled in insight. They will just run till soot load is 250% then auto shutdown. and then need a forced regen. Goes about 2 days and will need another regen again. Trucks are tarped have force air heaters blowing under them. Just looking for any advise to fix this issue other than demaindating them. The one truck face plugged within 200hrs and was fixed under warranty and the other 500hrs. Thanks