He’s back 
I’ll also keep an eye from now on. 
s2Member sending request to Cancel Subscription to Stripe
So, I am unsure if it will work, but this is my test, where I intentionally neuter Stripe’s Cancellation routines:
Inside the folder /wp-content/plugins/s2member-pro/src/includes/classes/gateways/stripe I modified a few files…
stripe-cancellation-in.inc.php
if(is_array($ipn_signup_vars = c_ws_plugin__s2member_utils_users::get_user_ipn_signup_vars()))
{
/* Deactivated Section Below and changed the Log Return to Reflect That
$ipn['txn_type'] = 'subscr_cancel';
$ipn['subscr_cid'] = $ipn_signup_vars['subscr_cid'];
$ipn['subscr_id'] = $ipn_signup_vars['subscr_id'];
$ipn['custom'] = $ipn_signup_vars['custom'];
$ipn['period1'] = $ipn_signup_vars['period1'];
$ipn['period3'] = $ipn_signup_vars['period3'];
$ipn['payer_email'] = $ipn_signup_vars['payer_email'];
$ipn['first_name'] = $ipn_signup_vars['first_name'];
$ipn['last_name'] = $ipn_signup_vars['last_name'];
$ipn['option_name1'] = $ipn_signup_vars['option_name1'];
$ipn['option_selection1'] = $ipn_signup_vars['option_selection1'];
$ipn['option_name2'] = $ipn_signup_vars['option_name2'];
$ipn['option_selection2'] = $ipn_signup_vars['option_selection2'];
$ipn['item_name'] = $ipn_signup_vars['item_name'];
$ipn['item_number'] = $ipn_signup_vars['item_number'];
$ipn['s2member_paypal_proxy'] = 'stripe';
$ipn['s2member_paypal_proxy_use'] = 'pro-emails';
$ipn['s2member_paypal_proxy_verification'] = c_ws_plugin__s2member_paypal_utilities::paypal_proxy_key_gen();
c_ws_plugin__s2member_utils_urls::remote(home_url('/?s2member_paypal_notify=1'), $ipn, array('timeout' => 20));
*/
}
Commented out the segment above, first line of the excerpt is number 89.
stripe-cancellation.inc.php
public static function stripe_cancellation()
{
/* Disabled the Function Below
if(!empty($_POST['s2member_pro_stripe_cancellation']))
c_ws_plugin__s2member_pro_stripe_cancellation_in::stripe_cancellation();
*/
}
I added the return false and I commented out the original. Not sure what this does but hopefully it cripples one item necessary.
stripe-utilities.inc.php
try // Attempt to cancel the subscription for this customer.
{
/* Deactivated Routines Below
// Check for draft/open invoice and void.
$subscription = \Stripe\Subscription::retrieve($subscription_id);
if (!empty($subscription->latest_invoice)) {
$latest_invoice = \Stripe\Invoice::retrieve($subscription->latest_invoice);
// If draft, finalize to change status to "open".
if ($latest_invoice->status == 'draft') {
$latest_invoice = $latest_invoice->finalizeInvoice([
'auto_advance' => false
]);
}
if ($latest_invoice->status == 'open') {
$latest_invoice = $latest_invoice->voidInvoice();
}
}
// Delete subscription if cancel now, update if at period end.
if ($cancel_at_period_end) {
$subscription = \Stripe\Subscription::update(
$subscription_id,
array('cancel_at_period_end' => true)
);
} else {
$subscription = \Stripe\Subscription::retrieve($subscription_id);
$subscription = $subscription->delete();
}
self::log_entry(__FUNCTION__, $input_time, $input_vars, time(), $subscription);
return $subscription; // Stripe subscription object.
*/
}
Again, commented out that segment to disable it.
I am pretty sure what I am doing is extremely inelegant and might not work. Hopefully it won’t cause issues. Maybe @clavaque gives some feedback and tells me the same could be done with half line of code 
I’ll keep you all posted.
Just in case I did the same to paypal-cancellation.inc.php…
if (!class_exists ("c_ws_plugin__s2member_pro_paypal_cancellation"))
{
/**
* PayPal Cancellation Form processing.
*
* @package s2Member\PayPal
* @since 1.5
*/
class c_ws_plugin__s2member_pro_paypal_cancellation
{
/**
* Handles processing of Pro-Form cancellations.
*
* @package s2Member\PayPal
* @since 1.5
*
* @attaches-to ``add_action("init");``
*
* @return null|inner Return-value of inner routine.
*/
public static function paypal_cancellation ()
{
if (!empty($_POST["s2member_pro_paypal_cancellation"]))
{
/* Disabled Routine Below to Prevent Cancellations
if($GLOBALS["WS_PLUGIN__"]["s2member"]["o"]["paypal_payflow_api_username"])
return c_ws_plugin__s2member_pro_paypal_cancellation_pf_in::paypal_cancellation();
return c_ws_plugin__s2member_pro_paypal_cancellation_in::paypal_cancellation ();
*/
}
}
}
}
You can see the part I commented out near the end.
Also edited paypal-utilities.inc.php
/**
* Cancels a Payflow recurring profile.
*
* @package s2Member\PayPal
* @since 110531
*
* @param string $subscr_id A paid subscription ID (aka: Recurring Profile ID).
* @param string $baid A Billing Agreement ID (aka: BAID).
*
* @return boolean True if the profile was cancelled, else false.
*/
public static function payflow_cancel_profile($subscr_id = '', $baid = '')
{
/* Disabled Routine Below to Prevent Cancellations
$payflow['TRXTYPE'] = 'R';
$payflow['ACTION'] = 'C';
$payflow['TENDER'] = 'C';
$payflow['ORIGPROFILEID'] = $subscr_id;
if(($cancellation = c_ws_plugin__s2member_paypal_utilities::paypal_payflow_api_response($payflow)) && empty($cancellation['__error']))
if(!$baid || c_ws_plugin__s2member_pro_paypal_utilities::payflow_cancel_billing_agreement($baid))
return TRUE;
$payflow['TENDER'] = 'P';
if(($cancellation = c_ws_plugin__s2member_paypal_utilities::paypal_payflow_api_response($payflow)) && empty($cancellation['__error']))
if(!$baid || c_ws_plugin__s2member_pro_paypal_utilities::payflow_cancel_billing_agreement($baid))
return TRUE;
*/
return FALSE;
}
/**
* Cancels a Payflow Billing Agreement.
*
* @package s2Member\PayPal
* @since 130510
*
* @param string $baid A Billing Agreement ID (aka: BAID).
*
* @return boolean True if the agreement was cancelled, else false.
*/
public static function payflow_cancel_billing_agreement($baid = '')
{
/* Disabled Routine Below to Prevent Cancellations
$payflow['ACTION'] = 'U';
$payflow['TENDER'] = 'P';
$payflow['BAID'] = $baid;
$payflow['BA_STATUS'] = 'cancel';
if(($cancellation = c_ws_plugin__s2member_paypal_utilities::paypal_payflow_api_response($payflow)) && empty($cancellation['__error']))
return TRUE;
*/
return FALSE;
}
Those are just segments of the files, not their entirety! Make any modifications at your own risk!
I attached a zip with the three modified files.stripe.zip (15.5 KB)
Stay tuned for news!