That is a very smart way to avoid running out of labels. Clever thinking and I also know that it works because I tried it on my HP32SII.
The small problem of programs being renumbered after editing a previously one resulting in fewer or greater steps could be easily rectified by padding the end of each separate program with as many ENTER commands as required so that each new program started at a number evenly divisible by, for example, 50 or 100. Then it would simply be a matter of adding or subtracting as many ENTER commands as required to get the following program numbers back in step to their original numbers. Of course, ENTER commands by themselves do not affect the operation of a program.
Any news yet on the release date of the 33S?