Having fought with this issue for years on two yachts, basically cruisers that I've also raced, I conclude there's no "easy" or casual solution for these racer/cruiser designs. If you wish to carry the correct sails for the variety of conditions that you will face then you must also have the ability to change them during competition, which means you need a practiced crew. Roller-reefing headsails that use a foil are typically heavier than hanked ones due to (yes, optional) sun protection fabric and/or foam luffs; they don't hoist as quickly (friction), sometimes jumping the groove (at the feed), and they do not stay attached to the head-stay all along the luff when being changed. Thus, they have to be "man-handled", especially in high wind. Of course, a No. 3 is a small sail so changing to it might not be as difficult as going back to the larger one.
I would first explore all other methods (e.g., sail trim; mainsail reefing, especially flat reefing) to keeping the boat flat, including if necessary feathering the boat to the upwind mark if not too distant so you'll have the genny already up for the downwind. Yes, you probably will get bowled over rounding the leeward mark and coming back on the wind. If there is room (no other boat right over you), however, you might quickly just come up a bit higher (pinch/feather) to get set before working the boat to the next weather mark. If it's expected to be strong and gusty most of the time you're out (after the start) and you do have the No. 3, consider putting it on before you go out. If the other boats are fighting it, you'll eventually be zipping past them on the upwind leg(s). If the situation does allow it w/ no time loss, put the genny back on if the wind lightens, etc.
Of course, another possibility might be to order up a new genny with a somewhat flatter cut/draft for when you're racing; one that's more dialed in to the conditions you typically experience. That, in combination with flat reefing the mainsail and applying other trim techniques (including rail meat), might work out for you.