This seems terribly confusing. Why not use another clef symbol, one that unambiguously indicates the correct octave?
This is only your opinion, or guess. What you are proposing is replacing one set of symbols with another set. Neither of them are actually ambiguous. The alternative can easily be just as confusing to someone, perhaps even yourself.
An annotation like └ ─ ─ ─ 8vb ─ ─ ─ ┘ under a group of notes clearly shows where the transposition begins and ends and it can be inferred to which notes it applies.
Clefs have their own problems: they change the letter note values of staff lines. In the standard treble clef, the lowest staff line is an E, whereas in the standard bass clef, it is a G. Clefs take up horizontal space and two are needed to indicate the temporary change and the return to the original clef.
Someone confronted with a clef change might complain of the confusion caused by the changing note values of the staff lines, and opine that it would be less confusing to have an octave transposition indicated over a range of notes instead.
No matter the notation, the performer's brain has to adjust to the staff lines temporarily having different absolute note values. I suspect that the source of your difficulty may be that adjustment, rather than the means by which it is indicated. Once you are in the middle of that passage, you have gone past the transposing indication and are reading the individual note values. If you are struggling at that point, it must actually be the altered semantics of the staff lines that is the problem. In your mind you have associated the staff lines with absolute positions on the piano keyboard and are reluctant to liberate them to refer to other octaves.
Reading through transpositions is just another reading skill that has to be practiced.