Hi Omofar. I value your contribution but i would like to be more precise from my experience. Missing Marksheet or previous academic records is one of the common refusal reason as per the IRPA 219. Proposed Detailed Plan, simply Study Plan will detailed your previous academic and future prospect. Yes, it may seem not required from the checklist, but it is required as per the guidelines. I fail to understand when you say you only need standardized LOA, and then you say "applicant clear description of how relevant the intended program of choice is to their future career", I want to believe that statement means Study plan though it lacks previous background aspect.
We both know there are decisions based on previous academic background or work experience. and we both know VO have wide descreation to ask any documents apart from the basic one. My point is, if you have transcript but you chose not to submit because as you said you dont need to submit academic credentials for SP application, that can be misleading. Plus we are not here to give hopes or wrong advice. Another example, what does proof of traveling history has to do with SP? but again it is required to submit.. one member in this same group was refused SP because she was asked to provide IELTS results but she chose not to, and opt for general route. once you have refusal, it takes efforts to overcome another refusal..
Familiarize with below reason, and if you have time, Judicial Review Determination and members posted on this forum. You dont just need LOA, you need to include your previous academic records. There are basic requirements, and guidelines. From personal experience, in 2016 i submitted my application with LOA but I did not attach previous academic transcripts, and i was given 14days to upload through link, and i did so
Refusal Based on Qualifications, Previous Studies, Missing Mark Sheets, Academic Record, Level of Establishment, Language Abilities
"Sometimes the application may miss to provide any of the mark sheets resulting in refusal because the case officer might think that you may be hiding some information which is a serious issue"