Is it better to max out TSP and then contribute to an IRA if I'm over the income limit?

I make over the income limit for a Roth IRA so would need to do a backdoor roth every year. I have alternative income that puts me over the Roth IRA income limit but that only comes in once per year. I'm currently contributing 7% to my roth TSP, and my agency has 5% matching, but I'm nowhere near the $23k max TSP contribution per year. Would it be better tax wise to contribute the maximum amount to TSP and then do a backdoor roth every year?