Yes, you're right, extra flexibility with, as it would be in this case, very little extra complexity would be good.
So far I haven't in practice, found the steps to be too annoyingly inappropriate on my WS1088 with the UK band plan but I decided to try and check exactly what's in the UK band plan on my WS1088:
25.000000 to 26.960000 in 10kHz steps
26.965000 to 27.405000 in 10kHz steps (with 5kHz offset)
gap
27.601250 to 27.991250 in 10kHz steps (with +1.25kHz offset)
gap
29.510000 to 47.000000 in 10kHz steps
47.000000 to 47.995000 in 5kHz steps
gap
50.000000 to 52.000000 in 10kHz steps
52.000000 to 88.000000 in 12.5kHz steps
gap
108.000000 to 137.000000 in "8.33kHz" steps
137.000000 to 138.000000 in 5kHz steps
138.000000 to 220.000000 in 6.25kHz steps
220.000000 to 225.000000 in 5kHz steps
225.000000 to 400.000000 in 12.5kHz steps
400.000000 to 512.000000 in 6.25kHz steps
gap
806.000000 to 960.000000 in 12.5kHz steps
gap
1240.000000 to 1300.000000 in 6.25kHz steps
I think I have it right.
Is that the same as on the TRX-1?
I admit there is more wrong, or less than ideal there than I thought.
There are one or two weird gaps for no obvious reason like between the two blocks of UK CB frequencies around 27.5MHz though I guess the illegal users there usually use SSB rather than AM or FM.
Also why a gap at 48 to 50MHz and the 10m amateur band is mostly in a gap too, though the part you'd usually expect to hear scan-able, I mean AM or FM, stuff on is there.
A lot of stuff below 50MHz would be better with 5kHz step rather than 10kHz. 11m broadcast band for one.
Having the whole of the 4m amateur band in 12.5kHz steps is not idea either, the first part of it isn't channelised so you might need smaller steps, actually that probably applies to parts of most amateur bands.
Some people might want 8.33kHz steps only in the part of airband where they are already in use, and 25kHz steps in the rest.
I think the 5kHz steps from 220 to 225MHz must be left in from the US band plan. I don't think they're right for UK.
For 806 to 960MHz smaller steps would be good because much of what little is scan-able in there is small devices like wireless microphones that are liable to be off channel.
Finally, though I very very rarely hear anything happening there, it'd be nice if the whole of the UK 23cm amateur band could be included (1240 to 1325MHz).