Not familiar with your chassis, so no input on adjusting tag psi.
If you are only talking about running the steers on the tag for an additional year, as long as the dismount does not reveal any visual problems, I see not problems. Staggering the 8 tires into 6 and 2 at a time purchases over a two year period will allow spending the budget impact out too:)!
I'm in the school of 5-7 years, with 7 being the max, on aging out the tires. Sure, some tires manufactures say go to 10 with annual inspections. But seeing the damage of blowouts, and crashes as a result of blowouts - has always been my reasoning for the added safety edge of replacing tires within the 5-7 year cycle. (We just replaced 6 out of our 8 that were a little over 6 years of age. They are still in good shape, and the tire manger did a through inspection and felt I could have gone another season. I elected to replace them, as I had had problems finding young tires in my less popular size in the past, and he had a set that were under 3 months of age.)
Each has their own comfort level, and balance cost against risk.
Best to all, be safe, have fun,
Smitty