If you want closer spacing, it's more convenient if you used double chainrings. Otherwise If you haven't exceeded the max single chainring size, you could build a custom 11-34 Miche 11 speed cassette by mixing your own cogs. You have to ask a dealer to do it. But that's only 309% range. The 9-32 would be 355%.
I have 12-34 with 44/24 double, which gives me 14-72.6 gear inches, 519%. I mixed my own Shimano 10 speed cogs, 12,13,14,15,17,19,21,24,28,34. It gives me closer spacing at the top and big spacing at the bottom.