GPS Ji, since Punjab was under the control of the British, legally, BOTH of the Singhs Sabhas, had no option other than recognizing the British authority over Punjab.
Singh Sabha Amritsar were no rebels, in order to join Singh Sabha Amritsar and complimentary Khalsa Divan under Khem Singh Bedi, one had to swear allegiance to the British.
This is fully documented. As far as the British were concerned, a handful of people in Singh Sabha Amritsar believed in the "PIPE DREAM" of Dalip Singh's return.
Singh Sabha Lahore viewed this as an impractical exercise that would cause more harm to the Panth and instead focused on stopping the direct threat by the Arya Samajis, and Christian missionaries, and ongoing Hinduization of the Sikh community.
Just because Singh Sabha Lahor did not support the "PIPE DREAM" does not mean they were traitors. In fact, they were great visionaries, who though it was more important to fight the scourge of Brahamansim that had infected the Panth, and bring back Gurmat Rahit and philosophy. Rmember, Singh Sabha Lahore did 95% of the Sikhi parchar during the Singh Sabha movement.
You may call GurSikhs such as Prof. Gurmukh Singh and Giani Ditt Singh Ji traitors, etc, but the Panth recognizes them as true heroes and scholars who stood against the Brahmanization of the Panth.
Without them and their tireless efforts through the Singhs Sabha movement, Sikh would have continued to worship Hindu deities at Sri Dabar Sahib, and marry according to Bedi customs.
Prof. Gurmukh Singh was a true Sikh scholar, whose sacrificed and persevered for the Panth. Scholars like Bhai Vir Singh, Bhai Kahn Singh Nabha, worked hand in hand with this gem, only they knew the real value of his "heera".