I will add from myself, what cannot be set up in the filename preferences yet.
To abbreviate long suffixes such as "blended_fused" and projection names (predefined or defined by a user).
It took a long time to guess which one is which. I am still not sure when I see "_fused" - was it composed from a stack or from any arrangement?.
In the editor there are options to make panoramas "from stack" and "from any arrangement", in the saved files there are suffixes "_fused" and "_blended_fused".
The suffixes make filenames undesirably long.
The proposal is to introduce alternative suffixes "_stk" and "_any".
Projection names. Fortunately almost each of the projections begins with a different letter.
I use this scheme (everybody may use a different) "lastfile-pah-6c" what means
pah = panorama created by Hugin, 6 = number of images, c = cylindrical projection (I add it manually).
The most of projections can be one or two characters added automatically, e for equirectangular, m for mercator, p for panini, r for rectilinear, f for fisheye
for other projections the suffix may be two letters, st for stereographic, th for thoby...
or different single letters like u for Miller, l for albers, q for equisolid etc.