Faceless demo content does convert for SaaS, especially when the product has a clear visual workflow. The face matters more for building a personal brand than for demonstrating software.
On your specific questions from actual experience:
Format: Stay native to each platform. A 90 second TikTok and a 8 to 12 minute YouTube tutorial are different content types, not the same video at different lengths. YouTube rewards depth and watch time. TikTok and Reels reward a fast hook and a single clear takeaway. Repurposing the same cut to all three underperforms on all three.
Audio: Voiceover consistently outperforms silent with captions for software demos because you can explain what you are doing while showing it. Trending audio on TikTok works for reach but feels forced on tool demos and attracts the wrong audience. Use it sparingly or not at all for SaaS content.
YouTube SEO: Titles that match how someone would actually search for a problem your tool solves outperform clever titles. Chapters matter a lot for watch time because people can jump to the relevant section rather than dropping off. Descriptions with the first two lines doing the keyword work since that is what shows before the fold.
Hashtags: Largely decorative on YouTube. Still have some relevance on TikTok for category placement but not worth optimising heavily.
Realistic expectation for a new channel: Very low organic reach for the first 3 to 6 months. YouTube is a long game. Where faceless SaaS demos get faster traction is in search results for specific problem queries rather than algorithm driven discovery.
The fastest path to views early is targeting very specific long tail search queries rather than broad topics.
