Does that mean that characters that already use an item like that and are above level 4 are banned on your table, or is that an exeption to the rule that reworking a character is only allowed through level 1 to 4?
While I understand your concern, having access to those items with the starting TCP from level 4 and 5 means you can actually create characters that use suboptimal race/class combinations and require multiple high stats to work - but that comes at a quite high cost actually: These items need attunement, they cost TCP which then are not available to spend on a magic weapon or to save for a rare item at level 6, the affected stat can never be brought to 20, and multiclassing would still require the original stat to at least be a 13 in most cases.
On the other hand, single-stat dependant characters don’t need these items and would be mostly unaffected by that nerf, they still can have their main stat at 20 at level 4 and usable stats outside of that for roleplaying.
What about increasing the TCP costs instead or having the items set the respective stat to 17 rather than 19?
Also I think if we introduce a rule like this, it should be introduced for all tables, as a general rule, so that still every character can be used at every table of the right tier