I'm not sure I get what you're asking
The way I understand it, you should play at the lowest minimum table that will allow you to adhere to the constraints of your available bankroll...
Not really. There are many considerations in deciding on what table to play. $5 & $10 tables very rarely offer the best opportunities. Sometimes rules and numbers of decks are better at the higher limits. But more frequently the game is just better at higher limits because of fewer players.
Starting with a high bet for cover,sounds like you will be undercapitalized to deal with any violent standard deviation that
you might have to deal with.
That is the nature of cover. It is not starting out with a "high" bet (a relative term). A small spread generally means starting with "bigger" fraction of your big bet. A small spread is essentially a cover tactic. You should be sufficiently capitalized, but what you do with cover is decrease your win rate and increase your risk in order to make your advantage play look less obvious. With a top bet of 2 hands of $1200 I might generally have a minimum of $100 or even 2@ $100. But if I decided to really push it I might boldly use a single bet of $25 as a waiting bet. This is something that cover considerations generally do not allow. But this bigger spread will increase my win rate because I'll have less in action at negative ev counts and decrease my risk as well. But if I sit at $5 & $10 tables my rounds per hour will probaby be cut in half and the table limits may not accomodate my max bets.
This guy may have a top bet of $500. If he's been playing for a living it is probably not much smaller than that, certainly. Such a player may normally have a $25 or $50 minimum. You would not normally find such a player at a $5 or $10 table. But if he really wanted to push it with a 1:100 spread, he might start table hopping with $5 bets and then start pushing the big money out when he hit a hot shoe.