you can use things during samadhi, merit is dependent on what state the donated things are being used

[auto]

When a mendicant enters and remains in a limitless immersion of heart while using a robe …

Yassa, bhikkhave, bhikkhu cīvaraṃ paribhuñjamāno appamāṇaṃ cetosamādhiṃ upasampajja viharati, appamāṇo tassa puññābhisando kusalābhisando sukhassāhāro sovaggiko sukhavipāko saggasaṃvattaniko iṭṭhāya kantāya manāpāya hitāya sukhāya saṃvattati.

alms-food … lodging … bed and chair …Yassa, bhikkhave, bhikkhu piṇḍapātaṃ paribhuñjamāno … pe … yassa, bhikkhave, bhikkhu vihāraṃ paribhuñjamāno … pe … yassa, bhikkhave, bhikkhu mañcapīṭhaṃ paribhuñjamāno … pe ….

medicines and supplies for the sick, the overflowing of merit for the donor is limitless …
Yassa, bhikkhave, bhikkhu gilānappaccayabhesajjaparikkhāraṃ paribhuñjamāno appamāṇaṃ cetosamādhiṃ upasampajja viharati, appamāṇo tassa puññābhisando kusalābhisando sukhassāhāro sovaggiko sukhavipāko saggasaṃvattaniko iṭṭhāya kantāya manāpāya hitāya sukhāya saṃvattati.

Merit is dependent on what state the donated things are being used.

[coconut]

It's just saying that mind precedes all things. Limitless immersion is equivalent to jhanas. To be reborn in the brahma planes you need to have a lot of good merit. So if you can attain limitless immersion, you already have good karma.

[Jeff_]

When a mendicant enters and remains in a limitless immersion of heart while using a robe …

Yassa, bhikkhave, bhikkhu cīvaraṃ paribhuñjamāno appamāṇaṃ cetosamādhiṃ upasampajja viharati, appamāṇo tassa puññābhisando kusalābhisando sukhassāhāro sovaggiko sukhavipāko saggasaṃvattaniko iṭṭhāya kantāya manāpāya hitāya sukhāya saṃvattati.

alms-food … lodging … bed and chair …Yassa, bhikkhave, bhikkhu piṇḍapātaṃ paribhuñjamāno … pe … yassa, bhikkhave, bhikkhu vihāraṃ paribhuñjamāno … pe … yassa, bhikkhave, bhikkhu mañcapīṭhaṃ paribhuñjamāno … pe ….

medicines and supplies for the sick, the overflowing of merit for the donor is limitless …
Yassa, bhikkhave, bhikkhu gilānappaccayabhesajjaparikkhāraṃ paribhuñjamāno appamāṇaṃ cetosamādhiṃ upasampajja viharati, appamāṇo tassa puññābhisando kusalābhisando sukhassāhāro sovaggiko sukhavipāko saggasaṃvattaniko iṭṭhāya kantāya manāpāya hitāya sukhāya saṃvattati.

Merit is dependent on what state the donated things are being used.

So appamāṇaṃ cetosamādhiṃ is "limitless immersion of heart" here. Clearly it's a type of samadhi. Perhaps it is related to the brahmaviharas? Can anyone say more on this?

In any case, this is a great Sutta to know about since, like you say, you can use things during this samadhi. Whether or not this samadhi is equivalent to this or that jhana, I really don't know. That issue seems less interesting than the way the Buddha here makes it plain that one can dwell in very wholesome states of concentration while going about the day, and that doing so is a source of great merit for anyone who gives you gifts (I suppose respect can be considered a type of gift?)
----

To be reborn in the brahma planes you need to have a lot of good merit. So if you can attain limitless immersion, you already have good karma.

This Sutta is part of a series dealing with the benefits of generosity for the one who gives. It says

the overflowing of merit for the donor is limitless

Perhaps it is meant to inspire the monks to practice, so the gifts given to them will be of utmost benefit to the donors, besides the benefits to themselves.

[Inedible]

It is easy to get people to give you things without asking them to and without having to tell them about merit. When you are in the habit of giving to other people at least some of them will reciprocate.

[SteRo]

"Now what, monks, is noble right concentration with its supports & requisite conditions? Any singleness of mind equipped with these seven factors — right view, right resolve, right speech, right action, right livelihood, right effort, & right mindfulness — is called noble right concentration with its supports & requisite conditions.
...
This is the right view with effluents, siding with merit, resulting in acquisitions.
...
This is the right view that is noble, without effluents, transcendent, a factor of the path.
...
There is right livelihood with effluents, siding with merit, resulting in acquisitions; there is right livelihood that is noble, without effluents, transcendent, a factor of the path.

https://www.accesstoinsight.org/tipitak ... .than.html

[Inedible]

It may be an interesting quote, but what are you trying to say here?