unnecessary confusion w/ Convert cmd

[resolved]

if I use the convert command in Home
CONVERT(2_(km),99_(ft)) I get 6561.6…..
CONVERT(2_(km),1_(ft)) I get 6561.6…..
CONVERT(2_(km),0_(ft)) I get 6561.6…..
but
CONVERT(2_(km),_(ft)) I get an ERROR
or
Help's example
CONVERT(20_m,1_ft) I get 65.6167….

if I use the convert command in CAS
CONVERT(2_(km),99_(ft)) I get an ERROR
CONVERT(2_(km),1_(ft)) I get an ERROR
CONVERT(2_(km),0_(ft)) I get an ERROR
CONVERT(2_(km),_(ft)) I get an ERROR
or
Help's example
CONVERT(20_m,1_ft) I get an ERROR

if I use STO symbol in Home
2_(km)"triangle"99_(ft) I get an ERROR
2_(km)"triangle"1_(ft) I get an ERROR
2_(km)"triangle"0_(ft) I get an ERROR
but
2_(km)"triangle"_(ft) I get 6561.6…..

the above is true for CAS (wonderful)

in Home view if I type
2_(KM)"triangle"_FT I get an ERROR
in CAS view if I type the same
2_(KM)"triangle"_FT I get _[((1000.*_M)/_FT * 2. _FT])

There were other anomalies, but my mind broke I can't remember what they were. When using the CONVERT cmmd you have to put in a number before the second unit, (that is ANY number, a billion would do), but in the "triangle" cmmd you must NOT put in a number before the second unit. The 616 page manual says nothing about this anomaly.
Instead of just ERROR messages, can't HP just inform the user "This function only works in Home mode" This simple instruction would save hours of research and frustration for the users trying to figure which comma was misplaces, etc.