Thanks to all for your thoughts/insight/perspective.

I'm white male and won't be getting on with a regional until my early 40's. (Again, no prior 121 or professional flying experience.)

I wonder if my age means that I should prioritize getting on with 1 of the 3 WO's? In other words, is 'automatic' flow my best bet of getting on with a major at an older age? Assuming comparable TT/TPIC/other individual attributes, won't a major - or even an LCC - want to get their hooks into someone younger than me who can provide more years of service?