just tested on 7.6 and looks like problem fixed.
matcher works as expected with option sets and boot options!

matcher with option 93 works if value is HEX to catch arch uefi64: value = 0x0007 for example, i can assign specific pool to uefi64 clients (with option 93 = 0x0007) and its works as expected. but assigning specific option set to this matcher (with specific bootfile name) has no effect. [admin@Mikro...

same problem. can't find any documentation for new matcher. looks like option matcher works with limited range dhcp options. in dhcp debug, option 93 displayed as "Unknown(93)": default received request id 3471760989 from 0.0.0.0 '' flags = broadcast ciaddr = 0.0.0.0 chaddr = 08:00:27:2B:7...