Athough my mother is Iranian-Zoroastrian (not Parsi/Irani-Zoroastrian from India), I’ve been across both communities.
SOME (not all) Parsi & Irani Zoroastrians in India, are quite orthodox in their beliefs & practices. Often, do not believe in conversion to Zoroastrianism, and put a protective ring around their community, either because of their interpretation of theology (per Sassanid period), or related community or family finances.
Tho, Zarathushtra (Zoroaster) himself was quite evangelical (and liberal, in a sense) in his teachings. There is absolutely nothing in the Gathas (the songs/hymns by Zoroaster) to suggest otherwise, about e.g. Towers of Silence, mixed marriages, etc.. How else would they’ve had so many Zoroastrians in Iran, or other parts of central Asia, before the advent of Islam, Judaism or Christianity??!
It’d be appropriate to bear in mind that some Zoroastrian priests in some (not all) communities in India, to date, maintain some of those *institutionalized Sassanid Zoroastrian practices*.
Equally, when they arrived in India centuries ago, they were accepted in the Indian community & allowed to remain there provided they did not proselytize. Also, post-Arab-Moslem invasion of Iran, many Zoroastrians ceased to accept converts because many Moslem converts were trying to infiltrate the Zoroastrian community to destroy them from within. So, the tradition seems to continue now, particularly with Parsi/Irani Zoroastrians in India.
The other consideration is that Zoroastrians in India, although of Persian (Parsi) and Iranian (Irani) heritage, they are NOW more mixed w/ Indian customs & traditions. So are many of their practices, which are mixed with the Hindu faith. Most do not speak Persian (unless those who have spent time in Iran, such as the ones, for example, I went to school with in Iran 3 decades ago).
true, many Parsis do have idols of Ganesha.