Hey! I was actually in a similar situation as you when I was first contemplating getting my BSW or just applying to the two year MSW program. This is just my opinion and people may not agree with me but I think in your case you should not get a BSW and, instead, take a year off to gain more human services/ social work experience. Your marks are amazing, the only thing that has probably prevented you from getting into your MSW is your experience. I would say 4,000 hours and up is usually more competitive (combined human service i.e. camp counselling, mental health hotline; and combined direct social work i.e. counselling, working at a homeless shelter, etc.). If you don't have your BSW it's hard to get a direct social work job but certainly not impossible you could work full time at a homeless shelter or at a community centre and rack up those hours.
My experience with my BSW was not the best. The BSW actually brought down my average and it was extremely stressful for me. And your BSW average will likely take precedence over what you have now. 96% average is insane and really hard to duplicate in the BSW. I was getting high 90s in my university courses but dropped to mid 80's in my BSW. Honestly, you seem like a super strong candidate. If i were you, I would apply to the CMHA support line for volunteering to get some hours and then work full time in a social work related job (cross cultural centre, community centre, homeless shelter, non for profit organization, swis worker, etc.). Once you accumulate those hours, I think you will be highly competitive. Not to mention, the BSW is two years which is a lot of time and commitment. You'll be busy completing school work and writing long essays (eek i hate long essays lol).
The extra practicum hours won't matter if you take a year off and work full time (as you'll accumulate more hours than in your BSW).
What i've heard is that the regular track and advanced standing MSWs are pretty even in terms of level of difficulty to get in. I know a number of friends who have been rejected to multiple schools post BSW.
The benefit of the BSW of course is that you can actually start practicing as a social worker and get direct social work experience. But because your marks are already so high I honestly believe you're a shoo in to get into your MSW once you increase your experience. So I would just focus on gaining those hours this year.
Sorry for the long reply, I hope this helps!