Akane and tinypoodle - thank you both for your dialog in response to my query. You did help me to resolve this issue.
First, the vga mode I wanted to embed as default:
vga mode: 356 [letter x]
resolution: 1152x864x32
is presented as an option when I choose scan on boot and even without scan. This is the best display mode this particular laptop can handle and as such I wanted to embed it as default.
Second, the last response by Akane, is the key to this solution. Instead of editing syslinux.cfg, I specified vga=0x356 during the install. This resulted in an installation that boots every time to this vga mode I wanted with no prompts or delays. Prefect. Thanks a bunch!!