Bear in mind that adult collectors, while a growing demographic, still comprise the minority of Transformers consumers. The majority are still kids. And even among adult collectors, I'd say that the majority of us do open our toys. According to
this poll, 79% of OTCAers play with their toys. 17.65% of respondents claim that they don't play with their toys, but that's not to necessarily say that they keep them sealed either, I don't know because there wasn't a separate option for this in the poll (perhaps I should make a new poll

). But let's say half of non-players are sealed collectors, that would make it 8.83% of OTCAers. Also bear in mind that consumers in Hasbro markets would also make up a relatively minority of TakaraTOMY's consumer base. Even if a lot of overseas collectors are purchasing their more collector-focused lines like MPs, the "bread and butter" of TFs even in Japan is still the mainline stuff aimed at kids, such as Transformers Adventures etc.
I don't think it makes good business sense for TakaraTOMY to invest in developing specially marked sticky tape to use on their toys in order to appease such a small demographic. Although there may be a lot of sealed collectors here, we don't necessarily represent the majority of the overall Transformers consumer base -- we represent part of the adult collector demographic. And the
Western adult collector demographic, thus we fall under Hasbro's jurisdiction, not TakaraTOMY's.
Ultimately, if you feel strongly enough about a suggestion, I think that the best place to submit it would be directly to TakaraTOMY themselves. Unfortunately their
online survey site is still geoblocked (although apparently there are ways to circumvent it if you're keen enough), however other avenues to contact them include:
Online Contact Form
Official Facebook Page
Telephone, Customer Call Centre*:
Standard Japanese = 0011-81-3-5650-1031
Osaka/Kansai Dialect = 0011-81-6-6395-1031
I would recommend using either the online survey
(if you can get around the geoblocking) or calling either Customer Call Centre [size"1"](if you can speak Japanese or have access to a Japanese speaker)[/size], as I've personally found those to be the most effective options. Especially the call centre one. I've never used their online contact form, and while I have posted on their FB page a few times, I've never had a response from TakaraTOMY, nor have I ever seen them act on anything that I've posted there. Anyway, just suggesting.
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*Bear in mind that
Golden Week is coming up, so TakaraTOMY will be closed during the public holidays that fall during this time.