Why staged beats sudden
A shop that moves overnight breaks in the places nobody tested: an old link in a pinned message, a customer who saved a page, a payment habit that no longer exists. Every one of those is an order, and you find out about them one complaint at a time, from the customers polite enough to complain.
Running both for a fortnight costs almost nothing and turns the decision into a measurement. It also means the day something does not work, the old shop is still there and nobody notices.
Week one: mirror the best sellers
Ten products, not the whole catalogue. Pick the ones that actually sell, because those are the ones whose behaviour you can compare against a known number. A slow product that stays slow in a new shop tells you nothing.
Each needs a name, a price, one good photo and the two lines that answer the question you always get about that product. You know what that question is. It is the one you have typed forty times.
The AI shop builder can do the first draft from a sentence describing your shop, and you edit everything after. It picks a design, writes the copy and fills a layout with example products in about a minute, which is faster than staring at an empty catalogue trying to decide on a colour.
Week one, second half: point the traffic
Put the shop button in your bot menu and mention it once in the channel, in a normal sentence rather than an announcement. You are not launching anything. You are seeing whether the people already talking to you buy more easily when the shop opens in the chat.
Resist the urge to promote it. A launch post brings a spike of curious people who were never going to buy, and their behaviour drowns the signal you are trying to read.
Week two: read the difference
Compare orders, not opinions. Look at how many people opened the shop against how many ordered, and at where the ones who did not order stopped: on the catalogue, on a product, or at the cart. Each of those three is a different problem with a different fix.
If the Mini App wins, widen the catalogue. If it does not, you know that too, and it cost you two weeks and no orders. That is a cheap answer to a question most sellers argue about for a year.
Then move the rest, slowly
Add products in batches with a few days between them, so that if something is wrong with how you are writing the descriptions you find out on batch two rather than on all two hundred.
Keep the old shop reachable until nothing points at it. Go through the pinned messages, the channel description, the bio, and anywhere you have ever posted a link. Old links are where orders quietly go missing, months after you thought the move was finished.
The part that is a conversation, not a setting
The last thing to move is the payment habit of your regulars. Someone who has sent you a transfer every month for two years is not going to change because a button changed, and they should not have to find out from a broken link.
Tell them directly, in the chat, once. That message is worth more than the whole migration plan.
What it costs to run the test
The free Mini App plan carries 10 products and 150 orders a month, which is exactly the size of the test described here. If you widen the catalogue afterwards, $19/mo takes it to 100 products and 1,500 orders, and adds card payments inside Telegram with the money going to your own Stripe account.